Current Electricity– 1 Practice Questions - DPP for NEET

 Page 1


DIRECTIONS (Q.1-Q.14) : There are 14 multiple choice
questions. Each question has 4 choices (a), (b), (c) and (d), out
of which ONLY ONE choice is correct.
Q.1 In the following fig. the ratio of current in 3W and 1W
resistances is–
(a) 1/3
(b) 2/3
3W
1W
3A
 X Y
6W
Z
(c)1
(d)2
Q.2 The resultant resistance between the points A and B in the
following fig. will be –
(a) 4 W
(b) 8 W
(c) 6 W
1W 1W 1W 1W
2W 2W 2W 1W
A
B
(d) 2 W
Q.3 H ow will reading in the ammeter
A be affected if an other
identical bulb Q is connected in
parallel to P as shown in the fig.
The voltage in the mains is
maintained at constant value
Mains
Switch
A 
P Q
(a) the reading will be reduced to one half.
(b) the reading will be double of previous one.
(c) the reading will not be affected.
(d) the reading will increase four fold.
Page 2


DIRECTIONS (Q.1-Q.14) : There are 14 multiple choice
questions. Each question has 4 choices (a), (b), (c) and (d), out
of which ONLY ONE choice is correct.
Q.1 In the following fig. the ratio of current in 3W and 1W
resistances is–
(a) 1/3
(b) 2/3
3W
1W
3A
 X Y
6W
Z
(c)1
(d)2
Q.2 The resultant resistance between the points A and B in the
following fig. will be –
(a) 4 W
(b) 8 W
(c) 6 W
1W 1W 1W 1W
2W 2W 2W 1W
A
B
(d) 2 W
Q.3 H ow will reading in the ammeter
A be affected if an other
identical bulb Q is connected in
parallel to P as shown in the fig.
The voltage in the mains is
maintained at constant value
Mains
Switch
A 
P Q
(a) the reading will be reduced to one half.
(b) the reading will be double of previous one.
(c) the reading will not be affected.
(d) the reading will increase four fold.
2
DPP/ P 36
Q.4 In the circuit shown, the galvanometer G reads zero. If
batteries have negligible internal resistances, the value of
resistance X wil be –
(a) 10 W
(b) 100 W
(c) 200 W
(d) 500 W
Q.5 A cylindrical wire is stretched to increase its length by
10%. The percentage increase in the resistance of the wire
will be–
(a) 20% (b) 21% (c) 22% (d) 24%
Q.6 In the figure, the equivalent resistance between A and B is–
(a) 2R/3
(b) R/3
(c)R
(d) 3R
Q.7 In the adjoining network of resistors, each is of resistance
r ohm, the equivalent resistance between points A and B is–
(a) 5r
(b) 2r/3
(c)r
(d) r/2.
Q.8 In the figure a carbon resistor has bands of different
colours on its body as mentioned in the figure. The value
of the resistance is
(a) 2.2 k W
(b) 3.3 k W
(c) 5.6 k W                 
White
Brown
Red
Silver
(d) 9.1 k W
Q.9 Two wires of same material have length L and 2L and cross-
sectional areas 4A and A respectively. The ratio of their
specific resistance would be
(a) 1 : 2 (b) 8 : 1 (c) 1 : 8 (d) 1 : 1
Q.10In the fig. shown, Calculate the current through 3 ohm
resistor. The emf of battery is 2 volt and its internal
resistance is 2/3 ohm.
(a) 0.33 amp. (b) 0.44 amp.
(c) 1.22 amp. (d) 0.88 amp.
Q.11 The current in the given circuit will be
(a)
1
A
45
(b)
1
A
15
(c)
1
A
10
               
2V
i
30 W
30 W
30 W
(d)
1
A
5
Q.12 The equivalent resistance of the following infinite network
of resistance is
2W 2W 2W
2W 2W 2W
2W 2W 2W
(a) Less than 4 W
(b)4W
(c) More than 4W but less than 12W
(d) 12 W
Q.13 A heater coil connected to a supply of a 220 V is dissipating
some power P
1
. The coil is cut into half and the two halves
are connected in parallel. The heater now dissipates a power
P
2
. The ratio of power P
1
 : P
2
 is
(a) 2 : 1 (b) 1 : 2 (c) 1 : 4 (d) 4 : 1
Page 3


DIRECTIONS (Q.1-Q.14) : There are 14 multiple choice
questions. Each question has 4 choices (a), (b), (c) and (d), out
of which ONLY ONE choice is correct.
Q.1 In the following fig. the ratio of current in 3W and 1W
resistances is–
(a) 1/3
(b) 2/3
3W
1W
3A
 X Y
6W
Z
(c)1
(d)2
Q.2 The resultant resistance between the points A and B in the
following fig. will be –
(a) 4 W
(b) 8 W
(c) 6 W
1W 1W 1W 1W
2W 2W 2W 1W
A
B
(d) 2 W
Q.3 H ow will reading in the ammeter
A be affected if an other
identical bulb Q is connected in
parallel to P as shown in the fig.
The voltage in the mains is
maintained at constant value
Mains
Switch
A 
P Q
(a) the reading will be reduced to one half.
(b) the reading will be double of previous one.
(c) the reading will not be affected.
(d) the reading will increase four fold.
2
DPP/ P 36
Q.4 In the circuit shown, the galvanometer G reads zero. If
batteries have negligible internal resistances, the value of
resistance X wil be –
(a) 10 W
(b) 100 W
(c) 200 W
(d) 500 W
Q.5 A cylindrical wire is stretched to increase its length by
10%. The percentage increase in the resistance of the wire
will be–
(a) 20% (b) 21% (c) 22% (d) 24%
Q.6 In the figure, the equivalent resistance between A and B is–
(a) 2R/3
(b) R/3
(c)R
(d) 3R
Q.7 In the adjoining network of resistors, each is of resistance
r ohm, the equivalent resistance between points A and B is–
(a) 5r
(b) 2r/3
(c)r
(d) r/2.
Q.8 In the figure a carbon resistor has bands of different
colours on its body as mentioned in the figure. The value
of the resistance is
(a) 2.2 k W
(b) 3.3 k W
(c) 5.6 k W                 
White
Brown
Red
Silver
(d) 9.1 k W
Q.9 Two wires of same material have length L and 2L and cross-
sectional areas 4A and A respectively. The ratio of their
specific resistance would be
(a) 1 : 2 (b) 8 : 1 (c) 1 : 8 (d) 1 : 1
Q.10In the fig. shown, Calculate the current through 3 ohm
resistor. The emf of battery is 2 volt and its internal
resistance is 2/3 ohm.
(a) 0.33 amp. (b) 0.44 amp.
(c) 1.22 amp. (d) 0.88 amp.
Q.11 The current in the given circuit will be
(a)
1
A
45
(b)
1
A
15
(c)
1
A
10
               
2V
i
30 W
30 W
30 W
(d)
1
A
5
Q.12 The equivalent resistance of the following infinite network
of resistance is
2W 2W 2W
2W 2W 2W
2W 2W 2W
(a) Less than 4 W
(b)4W
(c) More than 4W but less than 12W
(d) 12 W
Q.13 A heater coil connected to a supply of a 220 V is dissipating
some power P
1
. The coil is cut into half and the two halves
are connected in parallel. The heater now dissipates a power
P
2
. The ratio of power P
1
 : P
2
 is
(a) 2 : 1 (b) 1 : 2 (c) 1 : 4 (d) 4 : 1
DPP/ P 36
3
Q.14 An electric lamp is marked 60 W, 230 V. The cost of a 1
kWh of energy is ` 1.25. The cost of using this lamp 8 hrs
a day for 30 days is (approximately)
(a) ` 10 (b) ` 16 (c) ` 18 (d) ` 20
DIRECTIONS (Q.15-Q.17) : In the following questions,
more than one .of the answers  given are correct. Select the
correct answers and mark it according to the following
codes:
Codes :
(a) 1, 2 and 3 are correct (b) 1 and 2 are correct
(c) 2 and 4 are correct ( d) 1 and 3 are correct
Q.15 In the fig below the bulbs are identical, The bulbs, light
most brightly are
F
A
B C
Q P
E
D
(1) A (2) B (3) F (4) D
Q.16 An electric kettle has two heating coils. When one of the
coils is switched on, the water begins to boil in 6 minutes.
When the other is switched on, the boiling begins in 8
minutes. The time when the boiling begin if both coils are
switched on simultaneously is (i) in series (ii) in
parallel
(1) 14 min in series (2) 3.43 min in parallel
(3) 3.43 min in series (4) 14 min in parallel
Q.17 For the circuit shown in the figure
(1) The potential difference across R
L
 is 18 V
(2) The current I through the battery is 7.5 mA
(3) Ratio of powers dissipated in R
1
 and R
2
 is 3
(4) If R
1
 and R
2
 are interchanged magnitude of the power
dissipated in R
L
 will decrease by a factor of 9
DIRECTIONS (Q.18-Q.20) : Read the passage given below
and answer the questions that follows :
In the circuit shown in the figure,
12 V
5W
1W
Q.18 Rate of conversion of chemical energy within the battery
is
(a) 24 W (b) 20 W (c) 4 W (d) 14 W
Q.19Rate of dissipation of electrical energy in battery is
(a) 24 W (b) 20 W (c) 4 W (d) 14 W
Q.20 Rate of dissipation of electrical energy in external resistor
is
(a) 4 W (b) 20 W (c) 14 W (d) 24 W
DIRECTIONS (Q. 21-Q.23) : Each of these questions contains
two statements': Statement-1 (Assertion) and Statement-2
(Reason). Each of these questions has four alternative choices,
only one of which is the correct answer. You have to select the
correct choice.
(a) Statement-1 is True, Statement-2 is True; Statement-2 is a
correct explanation for  Statement-1.
(b) Statement-1 is True, Statement-2 is True; Statement-2 is
NOT a correct explanation for Statement-1.
(c) Statement -1 is False, Statement-2 is True.
(d) Statement -1 is True, Statement-2 is False.
Q.21 Statement-1 : The resistivity of a semiconductor decreases
with temperature.
Statement-2 : The atoms of a semiconductor vibrate with
larger amplitude at higher temperatures thereby increasing
its resistivity.
Page 4


DIRECTIONS (Q.1-Q.14) : There are 14 multiple choice
questions. Each question has 4 choices (a), (b), (c) and (d), out
of which ONLY ONE choice is correct.
Q.1 In the following fig. the ratio of current in 3W and 1W
resistances is–
(a) 1/3
(b) 2/3
3W
1W
3A
 X Y
6W
Z
(c)1
(d)2
Q.2 The resultant resistance between the points A and B in the
following fig. will be –
(a) 4 W
(b) 8 W
(c) 6 W
1W 1W 1W 1W
2W 2W 2W 1W
A
B
(d) 2 W
Q.3 H ow will reading in the ammeter
A be affected if an other
identical bulb Q is connected in
parallel to P as shown in the fig.
The voltage in the mains is
maintained at constant value
Mains
Switch
A 
P Q
(a) the reading will be reduced to one half.
(b) the reading will be double of previous one.
(c) the reading will not be affected.
(d) the reading will increase four fold.
2
DPP/ P 36
Q.4 In the circuit shown, the galvanometer G reads zero. If
batteries have negligible internal resistances, the value of
resistance X wil be –
(a) 10 W
(b) 100 W
(c) 200 W
(d) 500 W
Q.5 A cylindrical wire is stretched to increase its length by
10%. The percentage increase in the resistance of the wire
will be–
(a) 20% (b) 21% (c) 22% (d) 24%
Q.6 In the figure, the equivalent resistance between A and B is–
(a) 2R/3
(b) R/3
(c)R
(d) 3R
Q.7 In the adjoining network of resistors, each is of resistance
r ohm, the equivalent resistance between points A and B is–
(a) 5r
(b) 2r/3
(c)r
(d) r/2.
Q.8 In the figure a carbon resistor has bands of different
colours on its body as mentioned in the figure. The value
of the resistance is
(a) 2.2 k W
(b) 3.3 k W
(c) 5.6 k W                 
White
Brown
Red
Silver
(d) 9.1 k W
Q.9 Two wires of same material have length L and 2L and cross-
sectional areas 4A and A respectively. The ratio of their
specific resistance would be
(a) 1 : 2 (b) 8 : 1 (c) 1 : 8 (d) 1 : 1
Q.10In the fig. shown, Calculate the current through 3 ohm
resistor. The emf of battery is 2 volt and its internal
resistance is 2/3 ohm.
(a) 0.33 amp. (b) 0.44 amp.
(c) 1.22 amp. (d) 0.88 amp.
Q.11 The current in the given circuit will be
(a)
1
A
45
(b)
1
A
15
(c)
1
A
10
               
2V
i
30 W
30 W
30 W
(d)
1
A
5
Q.12 The equivalent resistance of the following infinite network
of resistance is
2W 2W 2W
2W 2W 2W
2W 2W 2W
(a) Less than 4 W
(b)4W
(c) More than 4W but less than 12W
(d) 12 W
Q.13 A heater coil connected to a supply of a 220 V is dissipating
some power P
1
. The coil is cut into half and the two halves
are connected in parallel. The heater now dissipates a power
P
2
. The ratio of power P
1
 : P
2
 is
(a) 2 : 1 (b) 1 : 2 (c) 1 : 4 (d) 4 : 1
DPP/ P 36
3
Q.14 An electric lamp is marked 60 W, 230 V. The cost of a 1
kWh of energy is ` 1.25. The cost of using this lamp 8 hrs
a day for 30 days is (approximately)
(a) ` 10 (b) ` 16 (c) ` 18 (d) ` 20
DIRECTIONS (Q.15-Q.17) : In the following questions,
more than one .of the answers  given are correct. Select the
correct answers and mark it according to the following
codes:
Codes :
(a) 1, 2 and 3 are correct (b) 1 and 2 are correct
(c) 2 and 4 are correct ( d) 1 and 3 are correct
Q.15 In the fig below the bulbs are identical, The bulbs, light
most brightly are
F
A
B C
Q P
E
D
(1) A (2) B (3) F (4) D
Q.16 An electric kettle has two heating coils. When one of the
coils is switched on, the water begins to boil in 6 minutes.
When the other is switched on, the boiling begins in 8
minutes. The time when the boiling begin if both coils are
switched on simultaneously is (i) in series (ii) in
parallel
(1) 14 min in series (2) 3.43 min in parallel
(3) 3.43 min in series (4) 14 min in parallel
Q.17 For the circuit shown in the figure
(1) The potential difference across R
L
 is 18 V
(2) The current I through the battery is 7.5 mA
(3) Ratio of powers dissipated in R
1
 and R
2
 is 3
(4) If R
1
 and R
2
 are interchanged magnitude of the power
dissipated in R
L
 will decrease by a factor of 9
DIRECTIONS (Q.18-Q.20) : Read the passage given below
and answer the questions that follows :
In the circuit shown in the figure,
12 V
5W
1W
Q.18 Rate of conversion of chemical energy within the battery
is
(a) 24 W (b) 20 W (c) 4 W (d) 14 W
Q.19Rate of dissipation of electrical energy in battery is
(a) 24 W (b) 20 W (c) 4 W (d) 14 W
Q.20 Rate of dissipation of electrical energy in external resistor
is
(a) 4 W (b) 20 W (c) 14 W (d) 24 W
DIRECTIONS (Q. 21-Q.23) : Each of these questions contains
two statements': Statement-1 (Assertion) and Statement-2
(Reason). Each of these questions has four alternative choices,
only one of which is the correct answer. You have to select the
correct choice.
(a) Statement-1 is True, Statement-2 is True; Statement-2 is a
correct explanation for  Statement-1.
(b) Statement-1 is True, Statement-2 is True; Statement-2 is
NOT a correct explanation for Statement-1.
(c) Statement -1 is False, Statement-2 is True.
(d) Statement -1 is True, Statement-2 is False.
Q.21 Statement-1 : The resistivity of a semiconductor decreases
with temperature.
Statement-2 : The atoms of a semiconductor vibrate with
larger amplitude at higher temperatures thereby increasing
its resistivity.
4
DPP/ P 36
Q.22 Statement-1 : In a simple battery circuit the point of lowest
potential is negative terminal of the battery .
Statement-2 : The current flows towards the point of the
higher potential as it flows in such a circuit from the
negative to the positive terminal.
Q.23 Statement-1 : The temperature coefficient of resistance is
positive for metals and negative for p-type semiconductor.
Statement-2 : The effective charge carriers in metals are
negatively charged whereas in p-type semiconductor they
are positively charged.