# Unseen Passage

For Class 4 to Class 12

# Class 12 Physics Sample Paper Term 1 Set C

Please see below Class 12 Physics Sample Paper Term 1 Set C with solutions. We have provided Class 12 Physics Sample Papers with solutions designed by Physics teachers for Class 12 based on the latest examination pattern issued by CBSE. We have provided the following sample paper for Term 1 Class 12 Physics with answers. You will be able to understand the type of questions which can come in the upcoming exams.

## CBSE Sample Paper for Class 12 Physics Term 1 Set C

Section – A

This section consists of 25 multiple choice questions with overall choice to attempt any 20 questions. In case more than desirable number of questions are attempted, ONLY first 20 will be considered for evaluation.

Q. 1. Three concentric metallic spherical shells of radii R, 2R, 3R, are given charges Q1, Q2, Q3, respectively.
The surface charge densities on the outer surfaces of the shells are equal. Q1 : Q2 : Q3 is
(A) 1:4:9
(B) 1:2:3
(C) 3:2:1
(D) 9:4:1

A

Q. 2. Value of k in coulomb’s law depends on
(A) nature of medium between two charges
(B) distance between two charges
(C) magnitude of charges
(D) both (A) and (C)

A

Q. 3. Gold leaf electroscope can be charged by
(A) conduction
(B) induction
(D) both (A) and (B)

D

Q. 4. There is an electric field in X-direction If the work done in moving a charge 0.2C through a distance of 2m along a line making an angle 60° with x-axis is 2J, the value of E is
(A) 10 N/C
(B) 20 N/C
(C) 30 N/C
(D) 40 N/C

A

Q. 5. The study of the effect associated with electric field at rest is
(A) Magnetostatics
(B) Electrostatics
(C) Electromagnetism
(D) None of the above

B

Q. 6. If the terminals of a charged capacitor is touched by hand
(A) It may give us a shock
(B) It discharges through our body
(C) Nothing happens
(D) Both (A) and (B)

D

Q. 7. The electric field required to keep of charged body of mass of m and charge suspended freely
(A) mg/e
(B) mge
(C) e/mg
(D) em/g

A

Q. 8. Which of the following demonstrate the proper connection of voltmeter and ammeter?

D

Q. 9. In the following Wheatstone bridge the voltage across C and D points is

(A) 35 V
(B) 50 V
(C) 100 V
(D) 65 V

A

Q. 10. Combine three resistors 5 Ω, 4.5 Ω and 3 Ω in such a way that the total resistance of this combination is maximum.
(A) 12.5 Ω in series
(B) 12.5 Ω in parallel
(C) 13.5 Ω in series
(D) 13.5 Ω in parallel

A

Q. 11. [M-1L-3T3A2] is the dimension of
(A) resistivity
(B) conductivity
(C) resistance
(D) capacitance

B

Q. 12. The resistances of a wire at 20°C and 500°C are 20 Ω and 60 Ω respectively. Its resistance will be 25 Ω at temperature
(A) 50°C
(B) 60°C
(C) 70°C
(D) 80°C

D

Q. 13. Earth’s magnetic field is horizontal at
(A) magnetic equator
(B) magnetic pole
(C) geographic equator
(D) geographic pole

A

Q. 14. Angle between magnetic meridian and geographical meridian is
(A) angle of declination
(B) angle of dip
(C) magnetic latitude
(D) magnetic longitude

A

Q. 15. 1 tesla = _____ gauss.
(A) 104
(B) 10–4
(C) 107
(D) 10–7

A

Q. 16. A long hollow metal current carrying pipe produces magnetic field
(A) inside only
(B) outside only
(C) both (A) and (B)
(D) no magnetic field is produced

B

Q. 17. Energy in a current carrying coil is the form of
(A) magnetic field
(B) electric field
(C) both (A) and (B)
(D) dielectric strength

A

Q. 18. The force on a charged particle moving with velocity v is subjected to a magnetic field B is zero. It implies that
(A) the angle between v and B is 0°
(B) the angle between v and B is 180°
(C) the angle between v and B is 90°
(D) both (A) and (B)

D

Q. 19. Kinetic energy of a proton is _______ when it is is accelerated through 1V.
(A) 1 eV
(B) – 1 eV
(C) 1836 eV
(D) 1.6 × 10–19 eV

A

Q. 20. In a series LCR circuit, the voltage across each component L, R and C is 30V. The voltage across LC combination is
(A) 30 V
(B) 60 V
(C) 0 V
(D) 90 V

C

Q. 21. In a series LCR circuit, the voltages across component L, R and C are 50 V, 20 V, 40 V. The supply voltage is
(A) 110V
(B) 10√5
(C) 50V
(D) none of the above

B

Q. 22. A _____ H inductor shows 100 Ω reactance when connected to a 200 V 100 Hz supply.
(A) 1/π
(B) 1/2π
(C) π
(D) 2π

B

Q. 23. When an A.C. supply whose VRMS = 10 V is connected across a resistor 10Ω, the power loss is _______ W.
(A) 20 W
(B) 0
(C) 5 W
(D) 10 W

D

Q. 24. The reactance of a capacitor is XC. If capacitance and frequency both are doubled, the reactance becomes _____ .
(A) 2XC
(B) XC/2
(C) 4XC
(D) XC/4

D

Q. 25. A a.c. circuit is having voltage V and current I. The power dissipation is
(A) VI
(B) VI/2
(C) VI/√2
(D) Dependant on the phase difference between V and I.

D

Section – B

This section consists of 24 multiple choice questions with overall choice to attempt any 20 questions. In case more than desirable number of questions are attempted, ONLY first 20 will be considered for evaluation.

Q. 26. The magnitude of electric force, F is
(A) inversely proportional to the multiplication of both charges.
(B) directly proportional to the distance between both charges.
(C) inversely proportional to the square of the distance between both charges.
(D) constant.

C

Q. 27. The Electric field at a point is
(A) always continuous.
(B) continuous if there is no charge at that point.
(C) discontinuous only if there is a negative charge at that point.
(D) continuous if there is a charge at that point.

B

Q. 28. Consider a region inside which there are various types of charges but the total charge is zero. At points outside the region
(A) the electric field is necessarily zero.
(B) the electric field is due to the dipole moment of the charge distribution only.
(C) the dominant electric field is proportional to 1/r3, for large r, where r is the distance from a origin in this region.
(D) the work done to move a charged particle along a closed path, away from the region, will be nonzero.

C

Q. 29. In a region of constant potential,
(A) the electric field is uniform.
(B) the electric field is non-zero.
(C) there can be no charge inside the region.
(D) the electric field shall necessarily change if a charge is placed outside the region.

C

Q. 30. If a conductor has a potential V ≠ 0 and there are no charges anywhere else outside, then
(A) there must be charges on the surface or inside itself.
(B) there must be charges in the body of the conductor.
(C) there must be charges only on the surface.
(D) there must be charges inside the surface.

A

Q. 31. The mutual inductance M12 of coil 1 with respect to coil 2
(A) decreases when they are brought nearer.
(B) depends on the current passing through the coils.
(C) increases when one of them is rotated about an axis.
(D) is the same as M21 of coil 2 with respect to coil 1.

D

Q. 32. As the frequency of an ac circuit increases, the current first increases and then decreases. What combination of circuit elements is most likely to comprise the circuit?
(A) Resistor
(B) Resistor and inductor
(C) Resistor and capacitor
(D) Resistor, inductor and capacitor

D

Q. 33. A polythene piece rubbed with wool is found to have a negative charge of 3 × 10–7 C. Amount of mass transfer from wool to polythene is
(A) 1.706 × 1018 kg
(B) 1.706 × 10–18 kg
(C) 3 × 10–7 kg
(D) 3 × 107 kg

B

Q. 34. The electrostatic force on a small sphere A of charge 0.4 μC due to another small sphere B of charge -0.8 μC in air is 0.2 N. What is the force on the B due to the A?
(A) 0.2 N
(B) 0
(C) Less than 0.2 N
(D) More than 0.2 N

A

Q. 35. Figure shows tracks of three charged particles in a uniform electrostatic field. Give the signs of the three charges.

(A) Positive, positive, negative
(B) Negative negative, positive
(C) Positive, negative, positive
(D) Negative, positive, negative

B

Q. 36. What is the value of dielectric constant for a metal
(A) Zero
(B) 1
(C) Infinity
(D) Both (A) and (C)

C

Q. 37. A metallic spherical shell has an inner radius R1 and outer radius R2. A charge Q is placed at the centre of the spherical cavity. What will be surface charge density on (i) the inner surface, and (ii) the outer surface?
(A) (i) – Q/4πR12 (ii) + Q/4πR22
(B) (i) + Q/4πR12 (ii) – Q/4πR22
(C) (i) – Q/4πR12 (ii) – Q/4πR22
(D) (i) + Q/4πR12 (ii) + Q/4πR22

A

Q. 38. The amount of work done in moving a point charge Q around a circular arc of radius ‘r’ at the centre of which another point charge ‘q’ is located is

(A) Depends on the value of Q and q
(B) Depends on the value of r
(C) Both (A) and (B)
(D) 0

D

Q. 39. Two charges −q and +q are located at points (0, 0, – a) and (0, 0, a), respectively.
The electrostatic potential at the points (0, 0, z) is

B

Q. 40. Nichrome and copper wires of same length and same radius are connected in series. Resistivity of Nichrome is more than that of copper. Current I is passed through them. Which wire gets heated up more?
(A) Copper
(B) Nichrome
(C) Both will be equally heated
(D) None of the above

B

Q. 41. The magnitude of magnetic force per unit length on a wire carrying a current of 8 A and making an angle of 30° with the direction of a uniform magnetic field of 0.15 T is
(A) 6 N/m
(B) 0.06 N/m
(C) 0.6 N/m
(D) 0.6 N/cm

C

Q. 42. Consider a magnet surrounded by a wire with an on/off switch S in the figure. If the switch is thrown from the off position (open circuit) to the on position (closed circuit), will a current flow in the circuit?

(A) No.
(B) Yes. Magnitude will depend on the area of the coil
(C) Yes. Magnitude will depend on the strength of the current.
(D) Yes. An instantaneous current will flow.

A

Q. 43. A horizontal straight wire 10 m long extending from east to west is falling with a speed of 5.0 m/sec, at right angles to the horizontal component of the earth’s magnetic field, 0.30 × 10–4 Wbm–2.
What is the instantaneous value of the emf induced in the wire and in which direction?
(A) 1.5 mV, West to East
(B) 1.5 mV, East to West
(C) 1.5V, West to east
(D) 1.5V, East to West

A

Q. 44. If a L-C circuit is considered analogous to a harmonically oscillating spring block system, ______ energy of the L-C circuit would be analogous to _______ energy and _______ energy of L-C circuit is analogous to ______ energy?
(A) Magnetic, kinetic, electrical, potential
(B) Electrical, kinetic, Magnetic, potential
(C) Kinetic, Magnetic, Potential, Electrical
(D) Potential, Magnetic, kinetic, electrical

A

Given below are two statements labelled as Assertion (A) and Reason (R)

Directions: In the following questions, a statement of Assertion (A) and is followed by a statement of Reason (R). Mark the correct choice as:
(A) Both Assertion (A) and Reason (R) are true, and Reason(R) is the correct explanation of (A).
(B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
(C) Assertion (A) is true, but Reason (R) is false.
(D) Assertion (A) is false, but Reason (R) is true.

Q. 45. Assertion (A): Quality factor of a series LCR circuit is Q = 1/R √L/C
Reason (R): As bandwidth decreases, Q increases in a resonant LCR circuit.

B

Q. 46. Assertion (A): A step-up transformer converts input low AC voltage to output high AC voltage.
Reason (R): It violate the law of conservation of energy.

C

Q. 47. Assertion (A): Earth’s magnetic field does not affect the functioning of a moving coil galvanometer.
Reason (R): Earth’s magnetic field is too weak.

A

Q. 48. Assertion (A): In moving coil galvanometer, the coil is wound on a metallic frame.
Reason (R): The metallic frame helps in making steady deflection without oscillation.

A

Q. 49. Assertion (A): Meter bridge wire is generally made of Constantan.
Reason (R): Constantan has a very low temperature coefficient of resistance.

A

Section – C

This section consists of 6 multiple choice questions with an overall choice to attempt any 5. In case more than desirable number of questions are attempted, ONLY first 5 will be considered for evaluation.

Q. 50. A 44 mH inductor is connected to 220 V, 50 Hz ac supply. The rms value of the current in the circuit is
(A) 5A
(B) 15.92A
(C) 5 × 10–3A
(D) None of the above

B

Q. 51. Which one of the following statements is correct?
(A) Alloys of metals usually have less resistivity than that of their constituent metals.
(B) Alloys usually have much higher temperature coefficients of resistance than pure metals.
(C) The resistivity of the alloy Manganin increases rapidly with increase of temperature.
(D) The resistivity of a typical insulator (e.g., amber) is greater than that of a metal by a factor of the order of 1022.

D

CASE STUDY

Read the following text and answer the following questions on the basis of the same:

Capacitor Colour Code: Capacitor values as written on small capacitors are sometimes misleading. Letters like p (pico) or n (nano) are used in place of the decimal point to identify its position and the value of the capacitor.
For example, a capacitor labelled as n33 = 0.33nF, 8n2 = 8.2nF, 22n = 47nF and so on.
Sometimes capacitors are marked with the capital letter K to signify a value of Kilo pico-Farads. As for example, a capacitor with the markings of 100K would be 1000 × 100 pF = 100 Kpf = 100 nF. Sometimes, a three letter code consists of the two value digits and a multiplier. For example, the digits 471 = 47 × 10 = 470 pF, 332 = 33 × 100 = 3300 pf.
To reduce these confusions an International colour coding scheme was developed almost same as that of resistance colour code.

The value obtained from colour code is in pf.

Q. 52. What is the value of the capacitor if n27 is written on it?
(A) 0.27 nF
(B) 0.27 pF
(C) 27 nF
(D) 27 pF

A

Q. 53. Two capacitors marked as 221 and 220 respectively are joined in parallel. What is the total capacitance value?
(A) 441 pF
(B) 242 pF
(C) 242 nF
(D) 441 nF

B

Q. 54. 68K is written on a capacitor. What is its value?
(A) 68 pF
(B) 68 nF
(C) 68 μF
(D) None of these.

B

Q. 55. What is the value of the capacitor bearing a colour code: brown, green, brown?
(A) 15 pF
(B) 15 nF
(C) 15 nF
(D) 150 pF