Practical Physics- 2 Practice Questions - DPP for NEET

 Page 1


DIRECTIONS (Q.1-Q.26) : There are 26 multiple choice
questions. Each question has 4 choices (a), (b), (c) and (d), out
of which ONLY ONE choice is correct.
Q.1 In making an Ohm’s law circuit, which of the following
connection is correct?
(a) Voltmeter in series and ammeter in parallel
(b) Voltmeter in parallel and ammeter in series
(c) V oltmeter and ammeter both are in parallel
(d) Voltmeter and ammeter both are in series
Q.2 To calculate an unknown resistance with the help of a meter
bridge why is it advised to change the gap with the known
and unknown resistance?
(a) To eliminate the resistance of the connecting wire and
copper strip
(b) To include the resistance of the connecting wire and
copper strip
(c) To balance the known and unknown resistance.
(d) To eliminate the resistance of the gap.
Q.3 Potential gradient of a potentiometer is equal to
(a) e.m.f per unit length
(b) potential drop per unit length
(c) current per unit length
(d) resistance per unit length
Q.4 The refractive index of the material of a prism does not
depend on which of the following factor?
(a) Nature of the material
(b) Wavelength or colour of light
(c) Temperature
(d) Angle of the prism.
Page 2


DIRECTIONS (Q.1-Q.26) : There are 26 multiple choice
questions. Each question has 4 choices (a), (b), (c) and (d), out
of which ONLY ONE choice is correct.
Q.1 In making an Ohm’s law circuit, which of the following
connection is correct?
(a) Voltmeter in series and ammeter in parallel
(b) Voltmeter in parallel and ammeter in series
(c) V oltmeter and ammeter both are in parallel
(d) Voltmeter and ammeter both are in series
Q.2 To calculate an unknown resistance with the help of a meter
bridge why is it advised to change the gap with the known
and unknown resistance?
(a) To eliminate the resistance of the connecting wire and
copper strip
(b) To include the resistance of the connecting wire and
copper strip
(c) To balance the known and unknown resistance.
(d) To eliminate the resistance of the gap.
Q.3 Potential gradient of a potentiometer is equal to
(a) e.m.f per unit length
(b) potential drop per unit length
(c) current per unit length
(d) resistance per unit length
Q.4 The refractive index of the material of a prism does not
depend on which of the following factor?
(a) Nature of the material
(b) Wavelength or colour of light
(c) Temperature
(d) Angle of the prism.
2
DPP/ P 60
Q.5 A meter-bridge is based on the principle of
(a) Wheatstone bridge
(b) Variation of resistance with temperature
(c) Galvanometer
(d) None of these
Q.6 A potentiometer works on the principle that
(a) when a current flows through a wire of uniform
thickness and material, potential difference between
its two points is directly proportional to the length of
the wire between the two points
(b) when a current flows through a wire of uniform
thickness and material, potential difference between
its two points is inversely proportional to the length
of the wire between the points
(c) when a current flows through a wire of uniform
thickness and material, potential difference between
its two points doesn't depend on the length of the wire
between the points
(d) none of these
Q.7 Which of the following statement is wrong regarding a
p–n junction diode?
(a) When the p-type section is connected to the positive
terminal and the n-type section to the negative terminal
of the battery the diode is called forward biased
(b)   When the p-type section is connected to the negative
terminal and the n-type section to the positive terminal
of the battery the diode is said to be reverse biased
(c) When the diode is in reverse biased mode a forward
current flows
(d) When the diode is in forward biased mode a forward
current flows.
Q.8 A Zener diode operates on which of the following bias?
(a) Forward bias
(b) Reverse bias
(c) Both forward and reverse bias.
(d) No biasing is required for it.
Q.9 The transfer characteristics of a transistor means a plot of
(a) input voltage versus input current
(b) output voltage versus output current.
(c) output voltage versus input voltage
(d) input current versus output current.
Q.10Current gain is maximum in which of the following
configuration of a transistor ?
(a) common emitter configuration
(b) common base configuration
(c) common collector configuration
(d) equal in both common emitter and common base
configuration
Q.11 Which of the following operations will not increase the
sensitivity of a potentiometer?
(a) Increase in the number of wires of the potentiometer.
(b) Reducing the potential gradient.
(c) Increasing the current through the potentiometer
(d) Increasing the sensitivity of the galvanometer.
Q.12 Which two circuit components are connected in parallel
in the following circuit diagram ?
(a) Rheostat and voltmeter
(b) Voltmeter and ammeter
(c) Voltmeter and resistor
(d) Ammeter and resistor
Q.13A current of 4A produces a deflection of 30° in the
galvanometer. The figure of merit is
(a) 6.5 A/rad (b) 7.6 A/rad
(c) 7.5 A/rad (d) 8.0 A/rad
Q.14 Two potentiometers A and B having 4 wires and 10 wires,
each having 100 cm in length are used to compare e.m.f.
of 2 cells. Which one will give a larger balancing length?
(a) Balancing length doesn't depend on the total length
of the wire.
(b) Both A and B will give same balancing length
(c) Potentiometer B
(d) Potentiometer A
Q.15 An LED operates under which biasing condition?
(a) Forward bias
(b) Reverse bias
(c) Can operate both in forward and reverse bias
(d) No biasing is required.
Q.16 How are the currents flowing in the emitter, base and the
collector related to each other?
(a)I
c
 =I
b
 + I
e
(b)I
e
 =I
b
 + I
c
(c)I
b
 =I
e
 + I
c
(d)I
e
 =I
c
 – I
b
Page 3


DIRECTIONS (Q.1-Q.26) : There are 26 multiple choice
questions. Each question has 4 choices (a), (b), (c) and (d), out
of which ONLY ONE choice is correct.
Q.1 In making an Ohm’s law circuit, which of the following
connection is correct?
(a) Voltmeter in series and ammeter in parallel
(b) Voltmeter in parallel and ammeter in series
(c) V oltmeter and ammeter both are in parallel
(d) Voltmeter and ammeter both are in series
Q.2 To calculate an unknown resistance with the help of a meter
bridge why is it advised to change the gap with the known
and unknown resistance?
(a) To eliminate the resistance of the connecting wire and
copper strip
(b) To include the resistance of the connecting wire and
copper strip
(c) To balance the known and unknown resistance.
(d) To eliminate the resistance of the gap.
Q.3 Potential gradient of a potentiometer is equal to
(a) e.m.f per unit length
(b) potential drop per unit length
(c) current per unit length
(d) resistance per unit length
Q.4 The refractive index of the material of a prism does not
depend on which of the following factor?
(a) Nature of the material
(b) Wavelength or colour of light
(c) Temperature
(d) Angle of the prism.
2
DPP/ P 60
Q.5 A meter-bridge is based on the principle of
(a) Wheatstone bridge
(b) Variation of resistance with temperature
(c) Galvanometer
(d) None of these
Q.6 A potentiometer works on the principle that
(a) when a current flows through a wire of uniform
thickness and material, potential difference between
its two points is directly proportional to the length of
the wire between the two points
(b) when a current flows through a wire of uniform
thickness and material, potential difference between
its two points is inversely proportional to the length
of the wire between the points
(c) when a current flows through a wire of uniform
thickness and material, potential difference between
its two points doesn't depend on the length of the wire
between the points
(d) none of these
Q.7 Which of the following statement is wrong regarding a
p–n junction diode?
(a) When the p-type section is connected to the positive
terminal and the n-type section to the negative terminal
of the battery the diode is called forward biased
(b)   When the p-type section is connected to the negative
terminal and the n-type section to the positive terminal
of the battery the diode is said to be reverse biased
(c) When the diode is in reverse biased mode a forward
current flows
(d) When the diode is in forward biased mode a forward
current flows.
Q.8 A Zener diode operates on which of the following bias?
(a) Forward bias
(b) Reverse bias
(c) Both forward and reverse bias.
(d) No biasing is required for it.
Q.9 The transfer characteristics of a transistor means a plot of
(a) input voltage versus input current
(b) output voltage versus output current.
(c) output voltage versus input voltage
(d) input current versus output current.
Q.10Current gain is maximum in which of the following
configuration of a transistor ?
(a) common emitter configuration
(b) common base configuration
(c) common collector configuration
(d) equal in both common emitter and common base
configuration
Q.11 Which of the following operations will not increase the
sensitivity of a potentiometer?
(a) Increase in the number of wires of the potentiometer.
(b) Reducing the potential gradient.
(c) Increasing the current through the potentiometer
(d) Increasing the sensitivity of the galvanometer.
Q.12 Which two circuit components are connected in parallel
in the following circuit diagram ?
(a) Rheostat and voltmeter
(b) Voltmeter and ammeter
(c) Voltmeter and resistor
(d) Ammeter and resistor
Q.13A current of 4A produces a deflection of 30° in the
galvanometer. The figure of merit is
(a) 6.5 A/rad (b) 7.6 A/rad
(c) 7.5 A/rad (d) 8.0 A/rad
Q.14 Two potentiometers A and B having 4 wires and 10 wires,
each having 100 cm in length are used to compare e.m.f.
of 2 cells. Which one will give a larger balancing length?
(a) Balancing length doesn't depend on the total length
of the wire.
(b) Both A and B will give same balancing length
(c) Potentiometer B
(d) Potentiometer A
Q.15 An LED operates under which biasing condition?
(a) Forward bias
(b) Reverse bias
(c) Can operate both in forward and reverse bias
(d) No biasing is required.
Q.16 How are the currents flowing in the emitter, base and the
collector related to each other?
(a)I
c
 =I
b
 + I
e
(b)I
e
 =I
b
 + I
c
(c)I
b
 =I
e
 + I
c
(d)I
e
 =I
c
 – I
b
DPP/ P 60
3
Q.17 The potential gradient of a potentiometer can be increased
by which of the following operation?
(a) By increasing the area of cross-section of the
potentiometer wire.
(b) By decreasing the area of cross-section of the
potentiometer wire.
(c) By decreasing the current through it.
(d) By using a wire of material of low specific resistance.
when A is decreased, k will increase.
Q.18 Of the diodes shown in the following diagrams, which one
is reverse biased ?
(a)
+5 V
+10 V
R
(b)   
–12 V
–5 V
R
(c)
–10 V
R
(d)   
+5 V
R
Q.19To determine the equivalent resistance of two resistors
when connected in series, a student arranged the circuit
components as shown in the diagram. But he did not
succeed to achieve the objective.
Which of the following mistakes has been committed by
him in setting up the circuit ?
(a) Position of voltmeter is incorrect
(b) Position of ammeter is incorrect
(c) Terminals of voltmeter are wrongly connected
(d) Terminals of ammeter are wrongly connected
Q.20 In the circuit shown, voltmeter is ideal and its least count
is 0.1 V . The least count of ammeter is 1 mA. Let reading
of the voltmeter be 30.0 V and the reading of ammeter is
0.020 A. Calculate the value of resistance R within error
limits.
(a) (1.5 
±
 0.05)kW
R
H
R V
A
E
(b) (1.2 
±
 0.05) k W
(c) (1.2 
±
 0.08) kW
(d) (1.5 
±
 0.08) kW
Q.21 In an experiment to measure the focal length of a concave
mirror, it was found that for an object distance of 0.30 m,
the image distance come out to be 0.60 m. Determine the
focal length.
(a) (0.2 
±
 0.01) m (b) (0.1 ± 0.01) m
(c) (0.2 
±
 0.02) m (d) (0.1 
±
 0.02) m
Q.22 In an experiment to determine an unknown resistance, a
100 cm long resistance wire is used. The unknown
resistance is kept in the left gap and a known resistance is
put into the right gap. The scale used to measure length has
a least count 1 mm. The null point B is obtained at 40.0 cm
from the left gap. Determine the percentage error in the
computation of unknown resistance.
(a) 0.24% (b) 0.28% (c) 0.50% (d) 0.42%
Q.23In an experiment to determine the focal length
(f ) of a concave mirror by the u - v method, a student places
the object pin  A on the principal axis at a distance x from
the pole P. The student looks at the pin and its inverted
image from a distance keeping his/her eye in line with PA.
When the student shifts his/her eye towards left, the image
appears to the right of the object pin. Then,
(a) x  <  f (b) f  <  x < 2f
(c) x  =  2f (d) x  >  2f
Q.24 For a convex spherical mirror, the graph of 
11
verses
vu
æö æö
ç÷ ç÷
èø èø
is
(a)
u
v 1/
1/
O
(b)
u
v 1/
1/
O
(c)
u
v 1/
1/
O
(d) 
u
v 1/
1/
O
Page 4


DIRECTIONS (Q.1-Q.26) : There are 26 multiple choice
questions. Each question has 4 choices (a), (b), (c) and (d), out
of which ONLY ONE choice is correct.
Q.1 In making an Ohm’s law circuit, which of the following
connection is correct?
(a) Voltmeter in series and ammeter in parallel
(b) Voltmeter in parallel and ammeter in series
(c) V oltmeter and ammeter both are in parallel
(d) Voltmeter and ammeter both are in series
Q.2 To calculate an unknown resistance with the help of a meter
bridge why is it advised to change the gap with the known
and unknown resistance?
(a) To eliminate the resistance of the connecting wire and
copper strip
(b) To include the resistance of the connecting wire and
copper strip
(c) To balance the known and unknown resistance.
(d) To eliminate the resistance of the gap.
Q.3 Potential gradient of a potentiometer is equal to
(a) e.m.f per unit length
(b) potential drop per unit length
(c) current per unit length
(d) resistance per unit length
Q.4 The refractive index of the material of a prism does not
depend on which of the following factor?
(a) Nature of the material
(b) Wavelength or colour of light
(c) Temperature
(d) Angle of the prism.
2
DPP/ P 60
Q.5 A meter-bridge is based on the principle of
(a) Wheatstone bridge
(b) Variation of resistance with temperature
(c) Galvanometer
(d) None of these
Q.6 A potentiometer works on the principle that
(a) when a current flows through a wire of uniform
thickness and material, potential difference between
its two points is directly proportional to the length of
the wire between the two points
(b) when a current flows through a wire of uniform
thickness and material, potential difference between
its two points is inversely proportional to the length
of the wire between the points
(c) when a current flows through a wire of uniform
thickness and material, potential difference between
its two points doesn't depend on the length of the wire
between the points
(d) none of these
Q.7 Which of the following statement is wrong regarding a
p–n junction diode?
(a) When the p-type section is connected to the positive
terminal and the n-type section to the negative terminal
of the battery the diode is called forward biased
(b)   When the p-type section is connected to the negative
terminal and the n-type section to the positive terminal
of the battery the diode is said to be reverse biased
(c) When the diode is in reverse biased mode a forward
current flows
(d) When the diode is in forward biased mode a forward
current flows.
Q.8 A Zener diode operates on which of the following bias?
(a) Forward bias
(b) Reverse bias
(c) Both forward and reverse bias.
(d) No biasing is required for it.
Q.9 The transfer characteristics of a transistor means a plot of
(a) input voltage versus input current
(b) output voltage versus output current.
(c) output voltage versus input voltage
(d) input current versus output current.
Q.10Current gain is maximum in which of the following
configuration of a transistor ?
(a) common emitter configuration
(b) common base configuration
(c) common collector configuration
(d) equal in both common emitter and common base
configuration
Q.11 Which of the following operations will not increase the
sensitivity of a potentiometer?
(a) Increase in the number of wires of the potentiometer.
(b) Reducing the potential gradient.
(c) Increasing the current through the potentiometer
(d) Increasing the sensitivity of the galvanometer.
Q.12 Which two circuit components are connected in parallel
in the following circuit diagram ?
(a) Rheostat and voltmeter
(b) Voltmeter and ammeter
(c) Voltmeter and resistor
(d) Ammeter and resistor
Q.13A current of 4A produces a deflection of 30° in the
galvanometer. The figure of merit is
(a) 6.5 A/rad (b) 7.6 A/rad
(c) 7.5 A/rad (d) 8.0 A/rad
Q.14 Two potentiometers A and B having 4 wires and 10 wires,
each having 100 cm in length are used to compare e.m.f.
of 2 cells. Which one will give a larger balancing length?
(a) Balancing length doesn't depend on the total length
of the wire.
(b) Both A and B will give same balancing length
(c) Potentiometer B
(d) Potentiometer A
Q.15 An LED operates under which biasing condition?
(a) Forward bias
(b) Reverse bias
(c) Can operate both in forward and reverse bias
(d) No biasing is required.
Q.16 How are the currents flowing in the emitter, base and the
collector related to each other?
(a)I
c
 =I
b
 + I
e
(b)I
e
 =I
b
 + I
c
(c)I
b
 =I
e
 + I
c
(d)I
e
 =I
c
 – I
b
DPP/ P 60
3
Q.17 The potential gradient of a potentiometer can be increased
by which of the following operation?
(a) By increasing the area of cross-section of the
potentiometer wire.
(b) By decreasing the area of cross-section of the
potentiometer wire.
(c) By decreasing the current through it.
(d) By using a wire of material of low specific resistance.
when A is decreased, k will increase.
Q.18 Of the diodes shown in the following diagrams, which one
is reverse biased ?
(a)
+5 V
+10 V
R
(b)   
–12 V
–5 V
R
(c)
–10 V
R
(d)   
+5 V
R
Q.19To determine the equivalent resistance of two resistors
when connected in series, a student arranged the circuit
components as shown in the diagram. But he did not
succeed to achieve the objective.
Which of the following mistakes has been committed by
him in setting up the circuit ?
(a) Position of voltmeter is incorrect
(b) Position of ammeter is incorrect
(c) Terminals of voltmeter are wrongly connected
(d) Terminals of ammeter are wrongly connected
Q.20 In the circuit shown, voltmeter is ideal and its least count
is 0.1 V . The least count of ammeter is 1 mA. Let reading
of the voltmeter be 30.0 V and the reading of ammeter is
0.020 A. Calculate the value of resistance R within error
limits.
(a) (1.5 
±
 0.05)kW
R
H
R V
A
E
(b) (1.2 
±
 0.05) k W
(c) (1.2 
±
 0.08) kW
(d) (1.5 
±
 0.08) kW
Q.21 In an experiment to measure the focal length of a concave
mirror, it was found that for an object distance of 0.30 m,
the image distance come out to be 0.60 m. Determine the
focal length.
(a) (0.2 
±
 0.01) m (b) (0.1 ± 0.01) m
(c) (0.2 
±
 0.02) m (d) (0.1 
±
 0.02) m
Q.22 In an experiment to determine an unknown resistance, a
100 cm long resistance wire is used. The unknown
resistance is kept in the left gap and a known resistance is
put into the right gap. The scale used to measure length has
a least count 1 mm. The null point B is obtained at 40.0 cm
from the left gap. Determine the percentage error in the
computation of unknown resistance.
(a) 0.24% (b) 0.28% (c) 0.50% (d) 0.42%
Q.23In an experiment to determine the focal length
(f ) of a concave mirror by the u - v method, a student places
the object pin  A on the principal axis at a distance x from
the pole P. The student looks at the pin and its inverted
image from a distance keeping his/her eye in line with PA.
When the student shifts his/her eye towards left, the image
appears to the right of the object pin. Then,
(a) x  <  f (b) f  <  x < 2f
(c) x  =  2f (d) x  >  2f
Q.24 For a convex spherical mirror, the graph of 
11
verses
vu
æö æö
ç÷ ç÷
èø èø
is
(a)
u
v 1/
1/
O
(b)
u
v 1/
1/
O
(c)
u
v 1/
1/
O
(d) 
u
v 1/
1/
O
4
DPP/ P 60
Q.25 If the wire in the experiment to determine the resistivity
of a material using meter bridge is replaced by copper or
hollow wire the balance point i.e. null point shifts to
(a) right (b) left
(c) at same point (d) none of these
Q.26 Which device is used to measure the potential difference
between two points of a conductor in the laboratory ?
(a) Voltameter (b) Ammeter
(c) Potentiometer (d) Galvanometer
DIRECTIONS (Q.27-Q.28) : Read the passage given below
and answer the questions that follows :
Consider a block of conducting material of resistivity ‘r’ shown
in the figure. Current ‘I’ enters at ‘A’ and leaves from ‘D’. We
apply superposition principle to find voltage ‘DV’ developed
between ‘B’ and ‘C’. The calculation is done in the following
steps:
(i) Take current ‘I’ entering from ‘A ’ and assume it to spread
over a hemispherical surface in the block.
(ii) Calculate field E(r) at distance ‘r’ from A by using  Ohm’s
law E = r j, where j is the current per unit area at ‘r’.
(iii) From the ‘r’ dependence of E(r),
obtain the potential V(r) at r.
(iv) Repeat (i), (ii) and (iii) for current
‘I’ leaving ‘D’ and superpose
results for ‘A ’ and ‘D’.
a
DV
A
I
B C D
b a
I
Q.27 DV measured between B and C is
(a)
II
–
a (a b)
rr
p p+
(b)
II
–
a (a b)
rr
+
(c)
II
–
2 a 2 (a b)
rr
p p+
(d)
I
2 (a b)
r
p-
Q.28 For current entering at A, the electric field at a distance ‘r’
from A is
(a)
2
I
8r
r
p
(b)
2
I
r
r
(c)
2
I
2r
r
p
(d)
2
I
4r
r
p