# Class 12 Physics Sample Paper With Solutions Set A

Please refer to Class 12 Physics Sample Paper With Solutions Set A below. These Class 12 Physics Sample Papers will help you to get more understanding of the type of questions expected in the upcoming exams. All sample guess papers for Physics Class 12 have been designed as per the latest examination pattern issued by CBSE. Please practice all CBSE Sample Papers for Physics in Standard 12.

## Sample Paper Class 12 Physics With Solutions Set A

1. Current versus time and voltage versus time graph of a circuit element is shown below The type of  the circuit element is

(a) capacitor of 2 F
(b) rsistor of 2 Ω
(c) capacitor of 1 F
(d) a voltage source of emf 1 V.

C

2. In the circuit shown in figure, charge stored in 4μF capacitor is

(a) 20 μC
(b) 40 μC
(c) 30 μC
(d) zero

A

3. Pick out the incorrect statement from the following :
(a) Mercury vapour lamp produces line emission spectrum.
(b) Oil flame produces line emission spectrum.
(c) Band spectrum helps us to study molecular structure.
(d) Sunlight spectrum is an example for line absorption spectrum.

B

4. A cell develops the same power across two resistances R1 and R2 separately. The internal resistance of the cell is

C

5. A voltmeter with resistance 500 Ω is used to measure the emf of a cell of internal resistance 4 Ω. The percentage error in the reading of the voltmeter will be
(a) 0.2%
(b) 0.8%
(c) 1.4%
(d) 2.2%

B

6. Pick out the correct statement from the following
(1) Electron emission during b-decay is always accompanied by neutrino.
(2) Nuclear force is charge independent.
(3) Fusion is the chief source of stellar energy.
(a) (1), (2) are correct
(b) (1), (3) are correct
(c) Only (1) is correct
(d) (2), (3) are correct

D

7. A battery of emf 10 V and internal resistance 3 Ω is connected to a resistor. The current in the circuit is 0.5 A. The terminal voltage of the battery when the circuit is closed, is
(a) 10 V
(b) 0 V
(c) 1.5 V
(d) 8.5 V

D

8. The current in the conductor varies with time t as I = 2t + 3t2 where I is in ampere and t in  seconds. Electric charge flowing through a section of conductor during t = 2 s to t = 3 s is
(a) 10 C
(b) 24 C
(c) 33 C
(d) 44 C

B

9. Which phenomenon best supports the theory that matter has a wave nature?
(a) Electron momentum
(b) Electron diffraction
(c) Photon momentum
(d) Photon diffraction

B

10. Logic gates X and Y have the truth tables shown below

When the output of X is connected to the input of Y, the resulting combination is equivalent to a single
(a) NOT gate
(b) OR gate
(c) NOR gate
(d) NAND gate

D

11. A transistor is operated in common-emitter configuration at constant collector voltage, Vc = 1.5 V such that a change in the base current from 100 mA to 150 mA produces a change in the collector current from 5 μA to 10 μA. The current gain is
(a) 67
(b) 75
(c) 100
(d) 50

C

12. In the given figure, the electron enters into the magnetic field as shown. It deflects in

(a) +ve X direction
(b) –ve X direction
(c) +ve Y direction
(d) –ve Y direction

D

13. In Young’s double slit experiment, intensity at a point is (1/4)th of the maximum intensity. Angular position of this point will be
(a) sin–1 (λ/d)
(b) sin–1 (λ/2d)
(c) sin–1 (λ/3d)
(d) sin–1 (λ/4d)

C

14. Magnetic field induction at the centre O of a square loop of side ‘a’ carrying current I as shown in figure is

D

15. Two wires of same length are shaped into a square and a circle. If they carry same current, ratio of their magnetic moments is
(a) 2 : π
(b) π : 2
(c) π : 4
(d) 4 : π

C

16. If a resistance of 100 Ω, an inductance of 0.5 H and a capacitance of 10 × 10–6 F are connected in series through 50 Hz ac supply, the impedance will be
(a) 1.87 Ω
(b) 101.3 Ω
(c) 18.7 Ω
(d) 189.7 Ω

D

17. Which gas is present in Gieger Muller Counter?
(a) Argon
(b) Neon
(c) Hydrogen
(d) Both (a) and (b)

D

18. Radiocarbon dating is based on the principle that all living matter possesses a certain amount of a radioactive form of
(a) Carbon
(b) Sodium
(c) Hydrogen
(d) Potassium

A

19. One requires 11 eV of energy to dissociate a carbon monoxide molecule into carbon and oxygen atoms. The minimum frequency of the appropriate electromagnetic radiation to achieve the dissociation lies in
(a) visible region
(b) infrared region
(c) ultraviolet region
(d) microwave region

C

20. A solenoid of 1.5 m length and 4.0 cm diameter possesses 10 turns per cm. A current of 5 A is  flowing through it. The magnetic induction at axis inside the solenoid is
(a) 2π × 10–3 T
(b) 2π × 10–5 T
(c) 2π × 10–2 G
(d) 2π × 10–5

A

21. The first antiparticle found was the
(a) positron
(b) hyperon
(c) quark
(d) baryon

A

22. A wire of length l is bent in the form of a circular coil of some turns. A current I flows through the coil. The coil is placed in a uniform magnetic field B. The maximum torque on the coil can be
(a) IBl2/2π
(b) IBl2/4π
(c) IBl2
(d) 2IBl2/π

B

23. A loop of area 0.5 m2 is placed in a magnetic field of strength 2 T in direction making an angle of 30° with the field. The magnetic flux linked with the loop will be

D

24. A long straight wire carrying current of 30 A rests on a table. Another wire AB of length 1 m, mass 3 g carries the same current but in the opposite direction, the wire AB is free to slide up and down. The height upto which AB will rise is
(a) 0.6 cm
(b) 0.7 cm
(c) 0.4 cm
(d) 0.5 cm

A

25. A circular coil of radius 10 cm having 100 turns carries a current of 3.2 A. The magnetic field at the centre of the coil is
(a) 2.01 × 10–3 T
(b) 5.64 × 10–3 T
(c) 2.64 × 10–4 T
(d) 5.01 × 10–4

A

26. A 2 mC charge moving around a circle with a frequency of 6.25 × 1012 Hz produces a magnetic field 6.28 T at the centre of the circle. The radius of the circle is
(a) 2.25 m
(b) 0.25 m
(c) 13.0 m
(d) 1.25 m

D

27. Four capacitors and a battery are connected as shown in the figure. If the potential difference across the 7 μF capacitor is 6 V, then which of the following statements is incorrect?
(a) The potential drop across the 12 μF capacitor is 10 V.
(b) The charge in the 3 μF capacitor is 42 μC.
(c) The potential drop across the 3 μF capacitor is 10 V.
(d) The emf of the battery is 30 V.

C

28. Light transmitted by Nicol prism is
(a) unpolarised
(b) plane polarised
(c) circularly polarised
(d) elliptically polarized.

B

29. In Newton’s rings experiment the diameter of 5th dark ring is reduced to half of its value after placing a liquid between plane glass plate and convex surface. Calculate the refractive index of liquid.
(a) 2
(b) 4
(c) √2
(d) 3

B

30. In a free space electron is placed in the path of a plane electromagnetic wave, it will start moving along
(a) centre of earth
(b) equator of earth
(c) magnetic field
(d) electric field

D

31. The radii of curvature of the two surfaces of a lens are 20 cm and 30 cm and the refractive index of the material of the lens is 1.5. If the lens is concavo-convex, then the focal length of the lens is
(a) 24 cm
(b) 10 cm
(c) 15 cm
(d) 120 cm

D

32. In the given circuit with steady current, the potential drop across the capacitor must be

(a) V
(b) V/2
(c) V/3
(d) 2V/3

C

33. In the circuit shown below, switch S is closed at a time t = 0. The charge which passes through the battery in one time constant is

(a) EL/eR2
(b) eL/ER
(c) eR2E/L
(d) E(L/R)

A

34. A sinusoidal voltage of peak value 300 V and an angular frequency ω = 400 rad s–1 is applied to series L-C-R circuit, in which R = 3 Ω, L = 20 mH and C = 625 μF. The peak current in the circuit is
(a) 30√2 A
(b) 60 A
(c) 100 A
(d) 60√2 A

B

35. The wavelength of the first spectral line in the Balmer series of hydrogen atom is 6561 Å. The wavelength of the second spectral line in the Balmer series of singly-ionized helium atom is
(a) 1215 Å
(b) 1640 Å
(c) 2430 Å
(d) 4687 Å

A

36. When an object is kept at a distance of 30 cm from a concave mirror, the image is formed at a distance of 10 cm. If the object is moved with a speed of 9 m s–1, the speed with which image moves is
(a) 10 m s–1
(b) 1 m s–1
(c) 9 m s–1
(d) 0.9 m s–1

B

37. When the electromagnetic radiations of frequencies 4 × 1015 Hz and 6 × 1015 Hz fall on the same metal, in different experiments, the ratio of maximum kinetic energy of electrons liberated is 1 : 3. The threshold frequency for the metal is
(a) 2 × 1015 Hz
(b) 1 × 1015 Hz
(c) 3 × 1015 Hz
(d) 4 × 1015 Hz

C

38. 37Li nucleus has three protons and four neutrons. Mass of 37Li nucleus is 7.016005 amu. Mass of proton is 1.007277 amu and mass of neutron is 1.008665 amu. Mass defect of lithium nucleus in amu is
(a) 0.04048
(b) 0.04050
(c) 0.04052
(d) 0.04055

A

39. In a nuclear reactor, moderators slow down the neutrons which come out in a fission process. The moderator used have light nuclei. Heavy nuclei will not serve the purpose because
(a) they will break up
(b) elastic collision of neutrons with heavy nuclei will not slow them down
(c) the net weight of the rector would be unbearably high
(d) substances with heavy nuclei do not occur in liquid or gaseous state at room  temperature