JEE  >  MCQ: Current Electricity, Class 12, Physics

# MCQ: Current Electricity, Class 12, Physics - Notes - JEE

``` Page 1

14  -  CURRENT  ELECTRICITY                                                 Page  1
( Answers  at  the  end  of  all  questions )

1 )   In  the  circuit,  the  galvanometer  G  shows  zero
deflection.  If  the  batteries  A  and  B  have  negligible
internal  resistance,  the  value  of  the  resistor  R  will
be
( a )     100 ?           ( b )   200 ?
( c )   1000 ?          ( d )   500?                        [ AIEEE  2005 ]

2 )    A  moving  coil  galvanometer  has  150  equal  divisions.  Its  current  sensitivity  is  10  divisions
per  milliampere  and  voltage  sensitivity  is  2  divisions  per  millivolt  In  order  that  each
division  reads  1  volt,  the  resistance  in  ohms  needed  to  be  connect d  in  series  with  the
coil  will  be
( a )   10
5
( b )   10
3
( c )   9995          ( d )   99995                                          [ AIEEE  2005 ]

3 )    Two  sources  of  equal  emf  are  connected  to  an  externa  resistance  R.  The  internal
resistances  of  the  two  sources  are  R
1
and  R
2
( R
2
>  R
1
).  If  the  potential  difference
across  the  source  having  internal  resistance  R
2
is  zero,  then
( a )
1
R R    R -
2
=     ( b )
2
2 1
2
R R
R  R
R    R
-
+
× =     ( c )
1 2
2 1
R R
R R
R
-
=     ( d )
2 1
2 1
R R
R R
R
+
=
[ AIEEE  2005 ]

4 )    In  a  potentiometer  experiment  the  balancing  with  a  cell  is  at  240  cm.  On  shunting  the
cell  with  a  resistance  of  2 ?  the  balancing  length  becomes  120  cm.  The  internal
resistance  of  the  cell  is
( a )   0.5 ?          ( b )   1 ?          ( c    2 ?          ( d )   4 ?                                                  [ AIEEE  2005 ]

5 )    The  resistance  of  hot  tungsten  ilament  is  about  10  times  the  cold  resistance.  What  will
be  the  resistance  of  100 W  and  200 V  lamp  when  not  in  use ?
( a )   20 ?          ( b )   40 ?          ( c )   200 ?          ( d )   400 ?                                        [ AIEEE  2005 ]

6 )    An  energy  source  will  upply  a  constant  current  into  the  load  if  its  internal  resistance  is
( a )   very  large  as  compared  to  the  load  resistance
( b )   equal  to  the  esistance  of  he  load
( c )   non- e o  but  less  than  the  resistance  of  the  load
( d )   ze o                                                                                                                           [ AIEEE  2005 ]

7 )    The  total  current  supplied  to  the  circuit  by  the  battery  is
( a )   1  A
( b )   2  A
( c )   4  A
d )   6  A                                            [ AIEEE  2004 ]

8 )    An  electric  current  is  passed  through  a  circuit  containing
two  wires  of  the  same  material,   connected  in  parallel.  If
the  lengths  and  radii  of  the  wires  are  in  the  ratio  of  4 / 3
and  2 / 3,  then  the  ratio  of  the  currents  passing  through
the  wires  will  be
( a )   3                 ( b )   1 / 3                ( c )   8 / 9                 ( d )   2                                 [ AIEEE  2004 ]

9 )    The  resistance  of  the  series  combination  of  two  resistors  is  S.  When  they  are  joined  in
parallel,  the  total  resistance  is  P.  If   S  =  nP,  then  the  minimum  possible  value  of  n  is
( a )   4               ( b )   3                      ( c )   2                      ( d )   1                                 [ AIEEE  2004 ]

www.examrace.com
Page 2

14  -  CURRENT  ELECTRICITY                                                 Page  1
( Answers  at  the  end  of  all  questions )

1 )   In  the  circuit,  the  galvanometer  G  shows  zero
deflection.  If  the  batteries  A  and  B  have  negligible
internal  resistance,  the  value  of  the  resistor  R  will
be
( a )     100 ?           ( b )   200 ?
( c )   1000 ?          ( d )   500?                        [ AIEEE  2005 ]

2 )    A  moving  coil  galvanometer  has  150  equal  divisions.  Its  current  sensitivity  is  10  divisions
per  milliampere  and  voltage  sensitivity  is  2  divisions  per  millivolt  In  order  that  each
division  reads  1  volt,  the  resistance  in  ohms  needed  to  be  connect d  in  series  with  the
coil  will  be
( a )   10
5
( b )   10
3
( c )   9995          ( d )   99995                                          [ AIEEE  2005 ]

3 )    Two  sources  of  equal  emf  are  connected  to  an  externa  resistance  R.  The  internal
resistances  of  the  two  sources  are  R
1
and  R
2
( R
2
>  R
1
).  If  the  potential  difference
across  the  source  having  internal  resistance  R
2
is  zero,  then
( a )
1
R R    R -
2
=     ( b )
2
2 1
2
R R
R  R
R    R
-
+
× =     ( c )
1 2
2 1
R R
R R
R
-
=     ( d )
2 1
2 1
R R
R R
R
+
=
[ AIEEE  2005 ]

4 )    In  a  potentiometer  experiment  the  balancing  with  a  cell  is  at  240  cm.  On  shunting  the
cell  with  a  resistance  of  2 ?  the  balancing  length  becomes  120  cm.  The  internal
resistance  of  the  cell  is
( a )   0.5 ?          ( b )   1 ?          ( c    2 ?          ( d )   4 ?                                                  [ AIEEE  2005 ]

5 )    The  resistance  of  hot  tungsten  ilament  is  about  10  times  the  cold  resistance.  What  will
be  the  resistance  of  100 W  and  200 V  lamp  when  not  in  use ?
( a )   20 ?          ( b )   40 ?          ( c )   200 ?          ( d )   400 ?                                        [ AIEEE  2005 ]

6 )    An  energy  source  will  upply  a  constant  current  into  the  load  if  its  internal  resistance  is
( a )   very  large  as  compared  to  the  load  resistance
( b )   equal  to  the  esistance  of  he  load
( c )   non- e o  but  less  than  the  resistance  of  the  load
( d )   ze o                                                                                                                           [ AIEEE  2005 ]

7 )    The  total  current  supplied  to  the  circuit  by  the  battery  is
( a )   1  A
( b )   2  A
( c )   4  A
d )   6  A                                            [ AIEEE  2004 ]

8 )    An  electric  current  is  passed  through  a  circuit  containing
two  wires  of  the  same  material,   connected  in  parallel.  If
the  lengths  and  radii  of  the  wires  are  in  the  ratio  of  4 / 3
and  2 / 3,  then  the  ratio  of  the  currents  passing  through
the  wires  will  be
( a )   3                 ( b )   1 / 3                ( c )   8 / 9                 ( d )   2                                 [ AIEEE  2004 ]

9 )    The  resistance  of  the  series  combination  of  two  resistors  is  S.  When  they  are  joined  in
parallel,  the  total  resistance  is  P.  If   S  =  nP,  then  the  minimum  possible  value  of  n  is
( a )   4               ( b )   3                      ( c )   2                      ( d )   1                                 [ AIEEE  2004 ]

www.examrace.com
14  -  CURRENT  ELECTRICITY                                                 Page  2
( Answers  at  the  end  of  all  questions )

10 )   In  a  meter  bridge  experiment,  null  point  is  obtained  at  20  cm  from  one  end  of  the  wire
when  resistance  X  is  balanced  against  another  resistance  Y.  If  X < Y,  then  where  will  be
the  new  position  of  the  null  point  from  the  same  end,  if  one  decides  to  balance  a
resistance  of  4X  against  Y ?
( a )   50  cm      ( b )   80  cm            ( c )   40  cm              ( d )   70  cm                       [ AIEEE  2004 ]

11 )    The  thermistors  are  usually  made  of
( a )   metals  with  low  temperature  coefficient  of  resistivity
( b )   metals  with  high  temperature  coefficient  of  resistivity
( c )   metal  oxides  with  high  temperature  coefficient  of  resistivity
( d )   semiconducting  materials  having  low  temperature  coefficient  of  esist vity
[ AIEEE  2004 ]

12 )   A  3  volt  battery  with  negligible  internal  resistance  is
connected  in  a  circuit  as  shown  in  the  figure.  The  cu rent
?  in  the  circuit  will  be
( a )   1 / 3  A      ( b )   1  A
( c )   1.5    A      ( d )   2  A
[ AIEEE  2003 ]

13 )   The  length  of  a  given  cylindrical  wire  is  increased   by  100  %.  Due  to  this  decrease  in
its  diameter,  the  change  in  the  resistance  of  t e  wire  will  be
( a )   300  %          ( b )   200  %          ( c )   100  %          ( d )   50  %                             [ AIEEE  2003 ]

14 )   An  ammeter  reads  upto  1  ampere  Its  internal  resistance  0.81  ohm.  To  increase  the
range  to  10  ampere,  the  value  of  the  r quired  shunt  is
( a )   0.09  ?         ( b )   0.03  ?         ( c )   0.3  ?            ( d )   0.9  ?                               [ AIEEE  2003 ]

15 )   The  length  of  a  wire  of  potentiometer  is  100  cm  and  the  e.m.f.  of  its  standard  cell  is  E
volt.  It  is  employed  to  measure  the  e.m.f.  of  a  battery  whose  internal  resistance  is  0.5  ?.
If  the  balance  point  is  obtained  at  l  =  30  cm  from  the  positive  end,  the  e.m.f.  of  the
battery  is
( a )   0.2 E            ( b )   0 3 E            ( c )   0.4 E             ( d )   0.5 E                              [ AIEEE   2003 ]
( Note:  The  concept  of  potentiometer  is  incorrectly  used  in  this  question.)

16 )   The  therm emf  of  a  thermocouple  is  25  µV / °C  at  room  temperature.  A  galvanometer  of
40  ?,  capable  of  detecting  current  as  low  as  10
- 5
A,  is  connected  with  the
thermocouple.  The  smallest  temperature  difference  that  can  be  detected  by  the  system  is
( a )  20 °C             ( b )   16 °C            ( c )   12 °C            ( d )   8 °C                               [ AIEEE   2003 ]

17    The  resistance  of  a  coil  at  100 °C  is  4.2  ?.  If  temperature  coefficient  of  resistance  is
0.004 / °C,  then  its  resistance  at  0 °C  is
( a )   6.5  ?            ( b )   5  ?                 ( c )   3  ?              ( d )   2.5  ?                            [ AIEEE   2002 ]

18 )   If  a  wire  of  resistance  R  is  melted  and  recasted  to  half  of  its  length,  then  the  new
resistance  of  the  wire  will  be
( a )   R / 4             ( b )   R / 2              ( c )   R                 ( d )   2 R                                  [ AIEEE  2002 ]

19 )   A  steady  current  flows  in  a  metallic  conductor  of  non-uniform  cross-section.  Which  of
the  following  quantity  is  constant  along  the  conductor ?
( a )  current     ( b )  drift  speed     ( c )  current  density     ( d )  none  of  these      [ AIEEE  2002 ]

www.examrace.com
Page 3

14  -  CURRENT  ELECTRICITY                                                 Page  1
( Answers  at  the  end  of  all  questions )

1 )   In  the  circuit,  the  galvanometer  G  shows  zero
deflection.  If  the  batteries  A  and  B  have  negligible
internal  resistance,  the  value  of  the  resistor  R  will
be
( a )     100 ?           ( b )   200 ?
( c )   1000 ?          ( d )   500?                        [ AIEEE  2005 ]

2 )    A  moving  coil  galvanometer  has  150  equal  divisions.  Its  current  sensitivity  is  10  divisions
per  milliampere  and  voltage  sensitivity  is  2  divisions  per  millivolt  In  order  that  each
division  reads  1  volt,  the  resistance  in  ohms  needed  to  be  connect d  in  series  with  the
coil  will  be
( a )   10
5
( b )   10
3
( c )   9995          ( d )   99995                                          [ AIEEE  2005 ]

3 )    Two  sources  of  equal  emf  are  connected  to  an  externa  resistance  R.  The  internal
resistances  of  the  two  sources  are  R
1
and  R
2
( R
2
>  R
1
).  If  the  potential  difference
across  the  source  having  internal  resistance  R
2
is  zero,  then
( a )
1
R R    R -
2
=     ( b )
2
2 1
2
R R
R  R
R    R
-
+
× =     ( c )
1 2
2 1
R R
R R
R
-
=     ( d )
2 1
2 1
R R
R R
R
+
=
[ AIEEE  2005 ]

4 )    In  a  potentiometer  experiment  the  balancing  with  a  cell  is  at  240  cm.  On  shunting  the
cell  with  a  resistance  of  2 ?  the  balancing  length  becomes  120  cm.  The  internal
resistance  of  the  cell  is
( a )   0.5 ?          ( b )   1 ?          ( c    2 ?          ( d )   4 ?                                                  [ AIEEE  2005 ]

5 )    The  resistance  of  hot  tungsten  ilament  is  about  10  times  the  cold  resistance.  What  will
be  the  resistance  of  100 W  and  200 V  lamp  when  not  in  use ?
( a )   20 ?          ( b )   40 ?          ( c )   200 ?          ( d )   400 ?                                        [ AIEEE  2005 ]

6 )    An  energy  source  will  upply  a  constant  current  into  the  load  if  its  internal  resistance  is
( a )   very  large  as  compared  to  the  load  resistance
( b )   equal  to  the  esistance  of  he  load
( c )   non- e o  but  less  than  the  resistance  of  the  load
( d )   ze o                                                                                                                           [ AIEEE  2005 ]

7 )    The  total  current  supplied  to  the  circuit  by  the  battery  is
( a )   1  A
( b )   2  A
( c )   4  A
d )   6  A                                            [ AIEEE  2004 ]

8 )    An  electric  current  is  passed  through  a  circuit  containing
two  wires  of  the  same  material,   connected  in  parallel.  If
the  lengths  and  radii  of  the  wires  are  in  the  ratio  of  4 / 3
and  2 / 3,  then  the  ratio  of  the  currents  passing  through
the  wires  will  be
( a )   3                 ( b )   1 / 3                ( c )   8 / 9                 ( d )   2                                 [ AIEEE  2004 ]

9 )    The  resistance  of  the  series  combination  of  two  resistors  is  S.  When  they  are  joined  in
parallel,  the  total  resistance  is  P.  If   S  =  nP,  then  the  minimum  possible  value  of  n  is
( a )   4               ( b )   3                      ( c )   2                      ( d )   1                                 [ AIEEE  2004 ]

www.examrace.com
14  -  CURRENT  ELECTRICITY                                                 Page  2
( Answers  at  the  end  of  all  questions )

10 )   In  a  meter  bridge  experiment,  null  point  is  obtained  at  20  cm  from  one  end  of  the  wire
when  resistance  X  is  balanced  against  another  resistance  Y.  If  X < Y,  then  where  will  be
the  new  position  of  the  null  point  from  the  same  end,  if  one  decides  to  balance  a
resistance  of  4X  against  Y ?
( a )   50  cm      ( b )   80  cm            ( c )   40  cm              ( d )   70  cm                       [ AIEEE  2004 ]

11 )    The  thermistors  are  usually  made  of
( a )   metals  with  low  temperature  coefficient  of  resistivity
( b )   metals  with  high  temperature  coefficient  of  resistivity
( c )   metal  oxides  with  high  temperature  coefficient  of  resistivity
( d )   semiconducting  materials  having  low  temperature  coefficient  of  esist vity
[ AIEEE  2004 ]

12 )   A  3  volt  battery  with  negligible  internal  resistance  is
connected  in  a  circuit  as  shown  in  the  figure.  The  cu rent
?  in  the  circuit  will  be
( a )   1 / 3  A      ( b )   1  A
( c )   1.5    A      ( d )   2  A
[ AIEEE  2003 ]

13 )   The  length  of  a  given  cylindrical  wire  is  increased   by  100  %.  Due  to  this  decrease  in
its  diameter,  the  change  in  the  resistance  of  t e  wire  will  be
( a )   300  %          ( b )   200  %          ( c )   100  %          ( d )   50  %                             [ AIEEE  2003 ]

14 )   An  ammeter  reads  upto  1  ampere  Its  internal  resistance  0.81  ohm.  To  increase  the
range  to  10  ampere,  the  value  of  the  r quired  shunt  is
( a )   0.09  ?         ( b )   0.03  ?         ( c )   0.3  ?            ( d )   0.9  ?                               [ AIEEE  2003 ]

15 )   The  length  of  a  wire  of  potentiometer  is  100  cm  and  the  e.m.f.  of  its  standard  cell  is  E
volt.  It  is  employed  to  measure  the  e.m.f.  of  a  battery  whose  internal  resistance  is  0.5  ?.
If  the  balance  point  is  obtained  at  l  =  30  cm  from  the  positive  end,  the  e.m.f.  of  the
battery  is
( a )   0.2 E            ( b )   0 3 E            ( c )   0.4 E             ( d )   0.5 E                              [ AIEEE   2003 ]
( Note:  The  concept  of  potentiometer  is  incorrectly  used  in  this  question.)

16 )   The  therm emf  of  a  thermocouple  is  25  µV / °C  at  room  temperature.  A  galvanometer  of
40  ?,  capable  of  detecting  current  as  low  as  10
- 5
A,  is  connected  with  the
thermocouple.  The  smallest  temperature  difference  that  can  be  detected  by  the  system  is
( a )  20 °C             ( b )   16 °C            ( c )   12 °C            ( d )   8 °C                               [ AIEEE   2003 ]

17    The  resistance  of  a  coil  at  100 °C  is  4.2  ?.  If  temperature  coefficient  of  resistance  is
0.004 / °C,  then  its  resistance  at  0 °C  is
( a )   6.5  ?            ( b )   5  ?                 ( c )   3  ?              ( d )   2.5  ?                            [ AIEEE   2002 ]

18 )   If  a  wire  of  resistance  R  is  melted  and  recasted  to  half  of  its  length,  then  the  new
resistance  of  the  wire  will  be
( a )   R / 4             ( b )   R / 2              ( c )   R                 ( d )   2 R                                  [ AIEEE  2002 ]

19 )   A  steady  current  flows  in  a  metallic  conductor  of  non-uniform  cross-section.  Which  of
the  following  quantity  is  constant  along  the  conductor ?
( a )  current     ( b )  drift  speed     ( c )  current  density     ( d )  none  of  these      [ AIEEE  2002 ]

www.examrace.com
14  -  CURRENT  ELECTRICITY                                                 Page  3
( Answers  at  the  end  of  all  questions )

20 )   Find  out  current  in  2 ?  resistance.

( a )   0    ( b )   2 A     ( c )   3 A     ( d )   5 A

[ IIT  2005 ]

21 )   A  galvanometer  of  resistance  100 ?  is  converted  to  an  ammeter  using  r sistance  of  0.1
?.  It  gives  full  scale  deflection  at 100  µA.  The  minimum  current  i  the  circuit  for
maximum  deflection  is
( a )   100.1  mA     ( b )   1000.1  mA     ( c )   1.001  mA     ( d )   10.01  mA                        [ IIT  2005 ]

22 )   A  rigid  container  with  thermally  insulated  walls  contains  a  coil  f  resistance   100  ?
carrying  current   1  A.  Change  in  internal  energy  after   5  minutes  is
( a )   0  kJ          ( b )   10  kJ          ( c )   20  kJ          ( d )   30  kJ                                        [ IIT  2005 ]

23 )   Six  equal  resistors  are  connected  between  point  P,  Q
and  R  as  shown  in  the  figure.  Then  the  next  esistance
will  be  maximum  between

( a )   P  and  Q          ( b )   Q  and  R

( c )   P  and  R          ( d )   any  two  points

[ IIT  2004 ]

24 )    For  the  post  office  b x  arrangement  to  determine  the
value  of  unknown  resistance,  the  unknown  resistance
should  be  connected  between
( a )   B    and  C
( b )   C    and  D
( c )   A    and  D
( d )   B
1
nd  C
1
[ IIT  2004 ]

25 )   Express  hich  of  the  following  set  ups  can  be  used  to  verify  Ohm’s  law ?

( a )                                         ( b )                                      ( c )                                      ( d )
[ IIT  2003 ]

26 )   The  temperature  coefficient  of  resistance  of  a  wire  is  0.00125  per  °C.  At   300 K   its
resistance  is   1  ohm.  The  resistance  of  the  wire  will  be   2  ohm  at
( a )   1154  K          ( b )   1100  K          ( c )   1400  K          ( d )   1127  K                          [ IIT  1980 ]

www.examrace.com
Page 4

14  -  CURRENT  ELECTRICITY                                                 Page  1
( Answers  at  the  end  of  all  questions )

1 )   In  the  circuit,  the  galvanometer  G  shows  zero
deflection.  If  the  batteries  A  and  B  have  negligible
internal  resistance,  the  value  of  the  resistor  R  will
be
( a )     100 ?           ( b )   200 ?
( c )   1000 ?          ( d )   500?                        [ AIEEE  2005 ]

2 )    A  moving  coil  galvanometer  has  150  equal  divisions.  Its  current  sensitivity  is  10  divisions
per  milliampere  and  voltage  sensitivity  is  2  divisions  per  millivolt  In  order  that  each
division  reads  1  volt,  the  resistance  in  ohms  needed  to  be  connect d  in  series  with  the
coil  will  be
( a )   10
5
( b )   10
3
( c )   9995          ( d )   99995                                          [ AIEEE  2005 ]

3 )    Two  sources  of  equal  emf  are  connected  to  an  externa  resistance  R.  The  internal
resistances  of  the  two  sources  are  R
1
and  R
2
( R
2
>  R
1
).  If  the  potential  difference
across  the  source  having  internal  resistance  R
2
is  zero,  then
( a )
1
R R    R -
2
=     ( b )
2
2 1
2
R R
R  R
R    R
-
+
× =     ( c )
1 2
2 1
R R
R R
R
-
=     ( d )
2 1
2 1
R R
R R
R
+
=
[ AIEEE  2005 ]

4 )    In  a  potentiometer  experiment  the  balancing  with  a  cell  is  at  240  cm.  On  shunting  the
cell  with  a  resistance  of  2 ?  the  balancing  length  becomes  120  cm.  The  internal
resistance  of  the  cell  is
( a )   0.5 ?          ( b )   1 ?          ( c    2 ?          ( d )   4 ?                                                  [ AIEEE  2005 ]

5 )    The  resistance  of  hot  tungsten  ilament  is  about  10  times  the  cold  resistance.  What  will
be  the  resistance  of  100 W  and  200 V  lamp  when  not  in  use ?
( a )   20 ?          ( b )   40 ?          ( c )   200 ?          ( d )   400 ?                                        [ AIEEE  2005 ]

6 )    An  energy  source  will  upply  a  constant  current  into  the  load  if  its  internal  resistance  is
( a )   very  large  as  compared  to  the  load  resistance
( b )   equal  to  the  esistance  of  he  load
( c )   non- e o  but  less  than  the  resistance  of  the  load
( d )   ze o                                                                                                                           [ AIEEE  2005 ]

7 )    The  total  current  supplied  to  the  circuit  by  the  battery  is
( a )   1  A
( b )   2  A
( c )   4  A
d )   6  A                                            [ AIEEE  2004 ]

8 )    An  electric  current  is  passed  through  a  circuit  containing
two  wires  of  the  same  material,   connected  in  parallel.  If
the  lengths  and  radii  of  the  wires  are  in  the  ratio  of  4 / 3
and  2 / 3,  then  the  ratio  of  the  currents  passing  through
the  wires  will  be
( a )   3                 ( b )   1 / 3                ( c )   8 / 9                 ( d )   2                                 [ AIEEE  2004 ]

9 )    The  resistance  of  the  series  combination  of  two  resistors  is  S.  When  they  are  joined  in
parallel,  the  total  resistance  is  P.  If   S  =  nP,  then  the  minimum  possible  value  of  n  is
( a )   4               ( b )   3                      ( c )   2                      ( d )   1                                 [ AIEEE  2004 ]

www.examrace.com
14  -  CURRENT  ELECTRICITY                                                 Page  2
( Answers  at  the  end  of  all  questions )

10 )   In  a  meter  bridge  experiment,  null  point  is  obtained  at  20  cm  from  one  end  of  the  wire
when  resistance  X  is  balanced  against  another  resistance  Y.  If  X < Y,  then  where  will  be
the  new  position  of  the  null  point  from  the  same  end,  if  one  decides  to  balance  a
resistance  of  4X  against  Y ?
( a )   50  cm      ( b )   80  cm            ( c )   40  cm              ( d )   70  cm                       [ AIEEE  2004 ]

11 )    The  thermistors  are  usually  made  of
( a )   metals  with  low  temperature  coefficient  of  resistivity
( b )   metals  with  high  temperature  coefficient  of  resistivity
( c )   metal  oxides  with  high  temperature  coefficient  of  resistivity
( d )   semiconducting  materials  having  low  temperature  coefficient  of  esist vity
[ AIEEE  2004 ]

12 )   A  3  volt  battery  with  negligible  internal  resistance  is
connected  in  a  circuit  as  shown  in  the  figure.  The  cu rent
?  in  the  circuit  will  be
( a )   1 / 3  A      ( b )   1  A
( c )   1.5    A      ( d )   2  A
[ AIEEE  2003 ]

13 )   The  length  of  a  given  cylindrical  wire  is  increased   by  100  %.  Due  to  this  decrease  in
its  diameter,  the  change  in  the  resistance  of  t e  wire  will  be
( a )   300  %          ( b )   200  %          ( c )   100  %          ( d )   50  %                             [ AIEEE  2003 ]

14 )   An  ammeter  reads  upto  1  ampere  Its  internal  resistance  0.81  ohm.  To  increase  the
range  to  10  ampere,  the  value  of  the  r quired  shunt  is
( a )   0.09  ?         ( b )   0.03  ?         ( c )   0.3  ?            ( d )   0.9  ?                               [ AIEEE  2003 ]

15 )   The  length  of  a  wire  of  potentiometer  is  100  cm  and  the  e.m.f.  of  its  standard  cell  is  E
volt.  It  is  employed  to  measure  the  e.m.f.  of  a  battery  whose  internal  resistance  is  0.5  ?.
If  the  balance  point  is  obtained  at  l  =  30  cm  from  the  positive  end,  the  e.m.f.  of  the
battery  is
( a )   0.2 E            ( b )   0 3 E            ( c )   0.4 E             ( d )   0.5 E                              [ AIEEE   2003 ]
( Note:  The  concept  of  potentiometer  is  incorrectly  used  in  this  question.)

16 )   The  therm emf  of  a  thermocouple  is  25  µV / °C  at  room  temperature.  A  galvanometer  of
40  ?,  capable  of  detecting  current  as  low  as  10
- 5
A,  is  connected  with  the
thermocouple.  The  smallest  temperature  difference  that  can  be  detected  by  the  system  is
( a )  20 °C             ( b )   16 °C            ( c )   12 °C            ( d )   8 °C                               [ AIEEE   2003 ]

17    The  resistance  of  a  coil  at  100 °C  is  4.2  ?.  If  temperature  coefficient  of  resistance  is
0.004 / °C,  then  its  resistance  at  0 °C  is
( a )   6.5  ?            ( b )   5  ?                 ( c )   3  ?              ( d )   2.5  ?                            [ AIEEE   2002 ]

18 )   If  a  wire  of  resistance  R  is  melted  and  recasted  to  half  of  its  length,  then  the  new
resistance  of  the  wire  will  be
( a )   R / 4             ( b )   R / 2              ( c )   R                 ( d )   2 R                                  [ AIEEE  2002 ]

19 )   A  steady  current  flows  in  a  metallic  conductor  of  non-uniform  cross-section.  Which  of
the  following  quantity  is  constant  along  the  conductor ?
( a )  current     ( b )  drift  speed     ( c )  current  density     ( d )  none  of  these      [ AIEEE  2002 ]

www.examrace.com
14  -  CURRENT  ELECTRICITY                                                 Page  3
( Answers  at  the  end  of  all  questions )

20 )   Find  out  current  in  2 ?  resistance.

( a )   0    ( b )   2 A     ( c )   3 A     ( d )   5 A

[ IIT  2005 ]

21 )   A  galvanometer  of  resistance  100 ?  is  converted  to  an  ammeter  using  r sistance  of  0.1
?.  It  gives  full  scale  deflection  at 100  µA.  The  minimum  current  i  the  circuit  for
maximum  deflection  is
( a )   100.1  mA     ( b )   1000.1  mA     ( c )   1.001  mA     ( d )   10.01  mA                        [ IIT  2005 ]

22 )   A  rigid  container  with  thermally  insulated  walls  contains  a  coil  f  resistance   100  ?
carrying  current   1  A.  Change  in  internal  energy  after   5  minutes  is
( a )   0  kJ          ( b )   10  kJ          ( c )   20  kJ          ( d )   30  kJ                                        [ IIT  2005 ]

23 )   Six  equal  resistors  are  connected  between  point  P,  Q
and  R  as  shown  in  the  figure.  Then  the  next  esistance
will  be  maximum  between

( a )   P  and  Q          ( b )   Q  and  R

( c )   P  and  R          ( d )   any  two  points

[ IIT  2004 ]

24 )    For  the  post  office  b x  arrangement  to  determine  the
value  of  unknown  resistance,  the  unknown  resistance
should  be  connected  between
( a )   B    and  C
( b )   C    and  D
( c )   A    and  D
( d )   B
1
nd  C
1
[ IIT  2004 ]

25 )   Express  hich  of  the  following  set  ups  can  be  used  to  verify  Ohm’s  law ?

( a )                                         ( b )                                      ( c )                                      ( d )
[ IIT  2003 ]

26 )   The  temperature  coefficient  of  resistance  of  a  wire  is  0.00125  per  °C.  At   300 K   its
resistance  is   1  ohm.  The  resistance  of  the  wire  will  be   2  ohm  at
( a )   1154  K          ( b )   1100  K          ( c )   1400  K          ( d )   1127  K                          [ IIT  1980 ]

www.examrace.com
14  -  CURRENT  ELECTRICITY                                                 Page  4
( Answers  at  the  end  of  all  questions )

27 )   In  the  sown  arrangement  of  the  experiment  of  the
meter  bridge  if  AC  corresponding  to  null  deflection
of  galvanometer  is  x,  what  would  be  its  value  if  the
radius  of  the  wire  AB  is  doubled ?

( a )  x     ( b )  x / 4     ( c )  4x     ( d )  2x
[ IIT  2003 ]

28 )   The  effective  resistance  between  points  P  and  Q  of  the
electrical  circuit  shown  in  the  figure  is

( a )
r R
Rr 2
+
( b )
r 3R
) r R  ( R 8
+
+

( c )   2r + 4R        ( d )   5R /2  +  2r                            [ IIT  2002 ]

29 )   The  potential  difference  applied  to  an  X ray  ube  is  5 kV  and  the  current  through  it  is
3.2  mA.  Then  the  number  of  electrons  st king  the  target  per  second  is
( a )  2 ×10
16
( b )  5 × 10
6
( c )  1 × 10
7
( d )  4 × 10
15
[ IIT  2002 ]

30 )   In  the  given  circuit,  with  st dy  urrent,  the  potential  drop
across  the  capacitor  must  be

( a )   V          ( b )   V / 2

( b )   V / 3     ( d )   2V / 3
[ IIT  2001 ]

31 )  In  the  given  circuit,  it  is  observed  that  the  current  ?  is
independent  of  the  value  of  the  resistance  R
6
.  Then  the
resistance  values  must  satisfy
( a )   R
1
R
2
R
5
= R
3
R
4
R
6

( b )
4 3 2 1 6 5
R  R
1

R  R
1

R
1

R
1
+
+
+
= +
( c )   R
1
R
4
=  R
2
R
3
( d )  R
1
R
2
=  R
2
R
4
[ IIT  2001 ]

32 )   In  the  circuit  shown,  P ? R.  The  reading  in
the  galvanometer  is  the  same  with  switch  S
open  or  closed.   Then

( a )   ?
R
=  ?
G
( b )   ?
P
=  ?
G

( c )   ?
Q
=  ?
G
( d )   ?
Q
=  ?
R
[ IIT  1999 ]

www.examrace.com
Page 5

14  -  CURRENT  ELECTRICITY                                                 Page  1
( Answers  at  the  end  of  all  questions )

1 )   In  the  circuit,  the  galvanometer  G  shows  zero
deflection.  If  the  batteries  A  and  B  have  negligible
internal  resistance,  the  value  of  the  resistor  R  will
be
( a )     100 ?           ( b )   200 ?
( c )   1000 ?          ( d )   500?                        [ AIEEE  2005 ]

2 )    A  moving  coil  galvanometer  has  150  equal  divisions.  Its  current  sensitivity  is  10  divisions
per  milliampere  and  voltage  sensitivity  is  2  divisions  per  millivolt  In  order  that  each
division  reads  1  volt,  the  resistance  in  ohms  needed  to  be  connect d  in  series  with  the
coil  will  be
( a )   10
5
( b )   10
3
( c )   9995          ( d )   99995                                          [ AIEEE  2005 ]

3 )    Two  sources  of  equal  emf  are  connected  to  an  externa  resistance  R.  The  internal
resistances  of  the  two  sources  are  R
1
and  R
2
( R
2
>  R
1
).  If  the  potential  difference
across  the  source  having  internal  resistance  R
2
is  zero,  then
( a )
1
R R    R -
2
=     ( b )
2
2 1
2
R R
R  R
R    R
-
+
× =     ( c )
1 2
2 1
R R
R R
R
-
=     ( d )
2 1
2 1
R R
R R
R
+
=
[ AIEEE  2005 ]

4 )    In  a  potentiometer  experiment  the  balancing  with  a  cell  is  at  240  cm.  On  shunting  the
cell  with  a  resistance  of  2 ?  the  balancing  length  becomes  120  cm.  The  internal
resistance  of  the  cell  is
( a )   0.5 ?          ( b )   1 ?          ( c    2 ?          ( d )   4 ?                                                  [ AIEEE  2005 ]

5 )    The  resistance  of  hot  tungsten  ilament  is  about  10  times  the  cold  resistance.  What  will
be  the  resistance  of  100 W  and  200 V  lamp  when  not  in  use ?
( a )   20 ?          ( b )   40 ?          ( c )   200 ?          ( d )   400 ?                                        [ AIEEE  2005 ]

6 )    An  energy  source  will  upply  a  constant  current  into  the  load  if  its  internal  resistance  is
( a )   very  large  as  compared  to  the  load  resistance
( b )   equal  to  the  esistance  of  he  load
( c )   non- e o  but  less  than  the  resistance  of  the  load
( d )   ze o                                                                                                                           [ AIEEE  2005 ]

7 )    The  total  current  supplied  to  the  circuit  by  the  battery  is
( a )   1  A
( b )   2  A
( c )   4  A
d )   6  A                                            [ AIEEE  2004 ]

8 )    An  electric  current  is  passed  through  a  circuit  containing
two  wires  of  the  same  material,   connected  in  parallel.  If
the  lengths  and  radii  of  the  wires  are  in  the  ratio  of  4 / 3
and  2 / 3,  then  the  ratio  of  the  currents  passing  through
the  wires  will  be
( a )   3                 ( b )   1 / 3                ( c )   8 / 9                 ( d )   2                                 [ AIEEE  2004 ]

9 )    The  resistance  of  the  series  combination  of  two  resistors  is  S.  When  they  are  joined  in
parallel,  the  total  resistance  is  P.  If   S  =  nP,  then  the  minimum  possible  value  of  n  is
( a )   4               ( b )   3                      ( c )   2                      ( d )   1                                 [ AIEEE  2004 ]

www.examrace.com
14  -  CURRENT  ELECTRICITY                                                 Page  2
( Answers  at  the  end  of  all  questions )

10 )   In  a  meter  bridge  experiment,  null  point  is  obtained  at  20  cm  from  one  end  of  the  wire
when  resistance  X  is  balanced  against  another  resistance  Y.  If  X < Y,  then  where  will  be
the  new  position  of  the  null  point  from  the  same  end,  if  one  decides  to  balance  a
resistance  of  4X  against  Y ?
( a )   50  cm      ( b )   80  cm            ( c )   40  cm              ( d )   70  cm                       [ AIEEE  2004 ]

11 )    The  thermistors  are  usually  made  of
( a )   metals  with  low  temperature  coefficient  of  resistivity
( b )   metals  with  high  temperature  coefficient  of  resistivity
( c )   metal  oxides  with  high  temperature  coefficient  of  resistivity
( d )   semiconducting  materials  having  low  temperature  coefficient  of  esist vity
[ AIEEE  2004 ]

12 )   A  3  volt  battery  with  negligible  internal  resistance  is
connected  in  a  circuit  as  shown  in  the  figure.  The  cu rent
?  in  the  circuit  will  be
( a )   1 / 3  A      ( b )   1  A
( c )   1.5    A      ( d )   2  A
[ AIEEE  2003 ]

13 )   The  length  of  a  given  cylindrical  wire  is  increased   by  100  %.  Due  to  this  decrease  in
its  diameter,  the  change  in  the  resistance  of  t e  wire  will  be
( a )   300  %          ( b )   200  %          ( c )   100  %          ( d )   50  %                             [ AIEEE  2003 ]

14 )   An  ammeter  reads  upto  1  ampere  Its  internal  resistance  0.81  ohm.  To  increase  the
range  to  10  ampere,  the  value  of  the  r quired  shunt  is
( a )   0.09  ?         ( b )   0.03  ?         ( c )   0.3  ?            ( d )   0.9  ?                               [ AIEEE  2003 ]

15 )   The  length  of  a  wire  of  potentiometer  is  100  cm  and  the  e.m.f.  of  its  standard  cell  is  E
volt.  It  is  employed  to  measure  the  e.m.f.  of  a  battery  whose  internal  resistance  is  0.5  ?.
If  the  balance  point  is  obtained  at  l  =  30  cm  from  the  positive  end,  the  e.m.f.  of  the
battery  is
( a )   0.2 E            ( b )   0 3 E            ( c )   0.4 E             ( d )   0.5 E                              [ AIEEE   2003 ]
( Note:  The  concept  of  potentiometer  is  incorrectly  used  in  this  question.)

16 )   The  therm emf  of  a  thermocouple  is  25  µV / °C  at  room  temperature.  A  galvanometer  of
40  ?,  capable  of  detecting  current  as  low  as  10
- 5
A,  is  connected  with  the
thermocouple.  The  smallest  temperature  difference  that  can  be  detected  by  the  system  is
( a )  20 °C             ( b )   16 °C            ( c )   12 °C            ( d )   8 °C                               [ AIEEE   2003 ]

17    The  resistance  of  a  coil  at  100 °C  is  4.2  ?.  If  temperature  coefficient  of  resistance  is
0.004 / °C,  then  its  resistance  at  0 °C  is
( a )   6.5  ?            ( b )   5  ?                 ( c )   3  ?              ( d )   2.5  ?                            [ AIEEE   2002 ]

18 )   If  a  wire  of  resistance  R  is  melted  and  recasted  to  half  of  its  length,  then  the  new
resistance  of  the  wire  will  be
( a )   R / 4             ( b )   R / 2              ( c )   R                 ( d )   2 R                                  [ AIEEE  2002 ]

19 )   A  steady  current  flows  in  a  metallic  conductor  of  non-uniform  cross-section.  Which  of
the  following  quantity  is  constant  along  the  conductor ?
( a )  current     ( b )  drift  speed     ( c )  current  density     ( d )  none  of  these      [ AIEEE  2002 ]

www.examrace.com
14  -  CURRENT  ELECTRICITY                                                 Page  3
( Answers  at  the  end  of  all  questions )

20 )   Find  out  current  in  2 ?  resistance.

( a )   0    ( b )   2 A     ( c )   3 A     ( d )   5 A

[ IIT  2005 ]

21 )   A  galvanometer  of  resistance  100 ?  is  converted  to  an  ammeter  using  r sistance  of  0.1
?.  It  gives  full  scale  deflection  at 100  µA.  The  minimum  current  i  the  circuit  for
maximum  deflection  is
( a )   100.1  mA     ( b )   1000.1  mA     ( c )   1.001  mA     ( d )   10.01  mA                        [ IIT  2005 ]

22 )   A  rigid  container  with  thermally  insulated  walls  contains  a  coil  f  resistance   100  ?
carrying  current   1  A.  Change  in  internal  energy  after   5  minutes  is
( a )   0  kJ          ( b )   10  kJ          ( c )   20  kJ          ( d )   30  kJ                                        [ IIT  2005 ]

23 )   Six  equal  resistors  are  connected  between  point  P,  Q
and  R  as  shown  in  the  figure.  Then  the  next  esistance
will  be  maximum  between

( a )   P  and  Q          ( b )   Q  and  R

( c )   P  and  R          ( d )   any  two  points

[ IIT  2004 ]

24 )    For  the  post  office  b x  arrangement  to  determine  the
value  of  unknown  resistance,  the  unknown  resistance
should  be  connected  between
( a )   B    and  C
( b )   C    and  D
( c )   A    and  D
( d )   B
1
nd  C
1
[ IIT  2004 ]

25 )   Express  hich  of  the  following  set  ups  can  be  used  to  verify  Ohm’s  law ?

( a )                                         ( b )                                      ( c )                                      ( d )
[ IIT  2003 ]

26 )   The  temperature  coefficient  of  resistance  of  a  wire  is  0.00125  per  °C.  At   300 K   its
resistance  is   1  ohm.  The  resistance  of  the  wire  will  be   2  ohm  at
( a )   1154  K          ( b )   1100  K          ( c )   1400  K          ( d )   1127  K                          [ IIT  1980 ]

www.examrace.com
14  -  CURRENT  ELECTRICITY                                                 Page  4
( Answers  at  the  end  of  all  questions )

27 )   In  the  sown  arrangement  of  the  experiment  of  the
meter  bridge  if  AC  corresponding  to  null  deflection
of  galvanometer  is  x,  what  would  be  its  value  if  the
radius  of  the  wire  AB  is  doubled ?

( a )  x     ( b )  x / 4     ( c )  4x     ( d )  2x
[ IIT  2003 ]

28 )   The  effective  resistance  between  points  P  and  Q  of  the
electrical  circuit  shown  in  the  figure  is

( a )
r R
Rr 2
+
( b )
r 3R
) r R  ( R 8
+
+

( c )   2r + 4R        ( d )   5R /2  +  2r                            [ IIT  2002 ]

29 )   The  potential  difference  applied  to  an  X ray  ube  is  5 kV  and  the  current  through  it  is
3.2  mA.  Then  the  number  of  electrons  st king  the  target  per  second  is
( a )  2 ×10
16
( b )  5 × 10
6
( c )  1 × 10
7
( d )  4 × 10
15
[ IIT  2002 ]

30 )   In  the  given  circuit,  with  st dy  urrent,  the  potential  drop
across  the  capacitor  must  be

( a )   V          ( b )   V / 2

( b )   V / 3     ( d )   2V / 3
[ IIT  2001 ]

31 )  In  the  given  circuit,  it  is  observed  that  the  current  ?  is
independent  of  the  value  of  the  resistance  R
6
.  Then  the
resistance  values  must  satisfy
( a )   R
1
R
2
R
5
= R
3
R
4
R
6

( b )
4 3 2 1 6 5
R  R
1

R  R
1

R
1

R
1
+
+
+
= +
( c )   R
1
R
4
=  R
2
R
3
( d )  R
1
R
2
=  R
2
R
4
[ IIT  2001 ]

32 )   In  the  circuit  shown,  P ? R.  The  reading  in
the  galvanometer  is  the  same  with  switch  S
open  or  closed.   Then

( a )   ?
R
=  ?
G
( b )   ?
P
=  ?
G

( c )   ?
Q
=  ?
G
( d )   ?
Q
=  ?
R
[ IIT  1999 ]

www.examrace.com
14  -  CURRENT  ELECTRICITY                                                 Page  5
( Answers  at  the  end  of  all  questions )

33 )   In  the  circuit  shown  in  the  figure,  the  current  through
( a )   the  3?  resistor  is  0.50  A
( b )   the  3?  resistor  is  0.25  A
( c )   the  4?  resistor  is  0.50  A
( d )   the  4?  resistor  is  0.25  A                             [ IIT  1998 ]

34 )   The  circuit  shown  in  the  figure  contains  two  diodes
each  with  a  forward  resistance  of   50  ?   and  with
infinite  backward  resistance.  If the  battery  voltage  is
6  V,   the  current  through  the   100  ?   resistor  ( in A )  is
( a )   zero          ( b )   0.02          ( c )   0.03          ( d )   0.036

[ IIT  1997

35 )    A  steady  current  flows  in  a  metallic  condu tor  o  non-uniform  cross-section.  The
quantity / quantities  constant  along  the  length  of  th  conductor  is / are
( a )   current,  electric  field  and  drift  velocity
( b )   drift  speed  only
( c )   current  and  drift  speed
( d )   current  only                                                                                                                 [ IIT  1997 ]

36 )    The  current   i   in  the  circuit  is

( a )   1 / 45  A           ( b )   1 / 15  A
( c )   1 / 10  A           ( d )    / 5  A

[ IIT  1983 ]

37 )    A  charge  of   3  C  experiences  a  force  of   3000  N    when  it  is  moved  in  a  uniform
electric  i ld  What  is  the  potential  difference  between  two  points  separated  by  a
distance    cm ?
( a )   10  V          ( b )   90  V          ( c )   1000  V          ( d )   100  V

38 )    A  cu ent   I   flows  in  a  wire  of  circular  cross-section  with  the  free  electrons  traveling
with  a  drift  velocity   V.   What  is  the  drift  velocity  of  electrons  when  a  current   2 I   flows
in  another  wire  of  twice  the  radius  and  of  the  same  material ?
a )   2 V          ( b )   V          ( c )          V / 2          ( d )   V / 4

39 )    A  piece  of  copper  wire  is  cut  into  ten  equal  parts.  These  parts  are  connected  in
parallel.  The  joint  resistance  of  the  parallel  combination  will  be  equal  to  the  original
resistance  of  the  uncut  wire,  multiplied  by  a  factor  of
( a )   0.01          ( b )   0.1          ( c )   1          ( d )   10

40 )   Using  the  resistors   R
1
and  R
2
singly,  in  series  and  in  parallel  combination,  we  can  get
4,  5,  20  and  25  ?.   Then   R
1
,   R
2
are
( a )   4,  5          ( b )   5,  20          ( c )   20,  25          ( d )   25,  4

www.examrace.com
```
 Use Code STAYHOME200 and get INR 200 additional OFF

Track your progress, build streaks, highlight & save important lessons and more!

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

;