# Class 12 Physics Sample Paper Term 1 With Solutions Set C

Please refer to Class 12 Physics Sample Paper Term 1 With Solutions Set C 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 Term 1 CBSE Sample Papers for Physics in Standard 12.

## Sample Paper Term 1 Class 12 Physics With Solutions 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. The magnitude of electric force, F is
(A) directly proportional to the multiplication of both charges.
(B) directly proportional to the distance between both charges.
(C) directly proportional to the square of the distance between both charges.
(D) constant.

A

Q. 2. A body is negatively charged means
(A) it has only negative charges.
(B) positive charges have been neutralized by negative charges.
(C) the quantity of negative charge present is more than the quantity positive charge present.
(D) the positive are displaced from their original positions.

C

Q. 3. When a body is charged by conduction, its mass
(A) remains same.
(B) increases.
(C) decreases.
(D) increase or decrease.

D

Q. 4. The electric potential at a point on the equatorial line of a electric dipole is
(A) directly proportional to the square of the distance.
(B) indirectly proportional to the square of the distance.
(C) directly proportional to the charge.
(D) None of the above

D

Q. 5. A capacitor of 4 μF is connected as shown in the circuit Figure. The internal resistance of the battery is 0.5 Ω. The amount of charge on the capacitor plates will be :

(A) 0 μC
(B) 4 μC
(C) 16 μC
(D) 8 μC

D

Q. 6. A parallel plate capacitor is made of two dielectric blocks in series. One of the blocks has thickness d1 and dielectric constant k1 and the other has thickness d2 and dielectric constant k2 as shown in Figure. This arrangement can be thought as a dielectric slab of thickness d (= d1+d2) and effective dielectric constant k. The k is :

C

Q. 7. In a metre bridge, what is the effect on null deflection of galvanometer, when the radius of the meter bridge wire is doubled?
(A) There will be no change
(B) Null point will shift to L1 / 2 point
(C) Null point will shift to 2L1 point
(D) Null point will not be available

A

Q. 8. Consider a metre bridge whose length of wire is 2 m. A resistance of 10 Ω is connected across one gap of the meter bridge and an unknown resistance is connected across the other gap. When these resistances are interchanged, the balance point shifts by 50 cm. What is the value of the unknown resistance?
(A) 250 Ω
(B) 10 Ω
(C) 16.7 Ω
(D) None of the above

C

Q. 9. A length L of wire carries a steady current I. It is bent first to form a circular plane coil of one turn. A current I flowing through it produces a magnetic field B at the centre of the coil. The same length is now bent more sharply to form a double loop of smaller radius. The magnetic field at the centre caused by the same current is
(A) B
(B) 2B
(C) 4B
(D) B/2

C

Q. 10. A straight conductor carries a current from south to north. Point P and Q lie to the east and west of it at the same distance. The magnetic field at P is
(A) equal to magnetic field at Q.
(B) smaller than the magnetic field at Q.
(C) greater than the magnetic field at Q.
(D) cannot be predicted unless the value if I is known.

A

Q. 11. Magnetic field due to a straight solenoid at any point inside it is B = μ0ni. Magnetic field at the end of the solenoid is
(A) B
(B) B/2
(C) 2B
(D) B/4

B

Q. 12. At any point, empty space surrounded by a toroid, the magnetic field is B1. At any point, outside the toroid, the magnetic field is B2.
(A) B1 > B2
(B) B2 > B1
(C) B1 = B2
(D) B1 = B2 = 0

D

Q. 13. Ratio of total intensity of magnetic field at equator to poles is
(A) 1 : 2
(B) 1 : 2
(C) 2 : 1
(D) None of the above

A

Q. 14. Let the magnetic field on Earth be modelled by that of a point magnetic dipole at the centre of Earth. The angle of dip at a point on the geographical equator
(A) is always zero.
(B) is always positive.
(C) is always negative.
(D) can be positive or negative or zero.

D

Q. 15. Relative permeability of a magnetic material is 0.5. The material is
(A) diamagnetic.
(B) ferromagnetic.
(C) paramagnetic.
(D) not a magnetic material.

A

Q. 16. Which of the following relation is correct?
(A) B = BV × BH
(B) B = BV / BH
(C) B = BV + BH
(D) B = √B2V B2H

D

Q. 17. Two identical capacitors are joined in parallel, charged to a potential V and then separated and then connected in series i.e. the positive plate of one is connected to negative of the other :
(A) The charges on the free plates connected together are destroyed.
(B) The charges on the free plates are enhanced.
(C) The energy stored in the system increases.
(D) The potential difference in the free plates becomes 2V.

C

Q. 18. Which one of the following statements is wrong?
(A) Eddy currents are produced in a steady magnetic field.
(B) Eddy current is used to produce braking force in moving trains.
(C) Eddy currents is minimized by using laminated core.
(D) Induction furnace uses eddy current to produce heat.

A

Q. 19. With increase in frequency of an A.C. supply, the impedance of a series L-C-R circuit
(A) remains constant.
(B) increases.
(C) decreases.
(D) decreases at first, becomes minimum and then increases.

D

Q. 20. An electric cable contains a single copper wire of radius 9 mm. It’s resistance is 5 Ω. This cable is replaced by six insulated copper wires, each of radius 3 mm. The resultant resistance of cable will be :

(A) 7.5 Ω
(B) 45 Ω
(C) 90 Ω
(D) 270 Ω

A

Q. 21. An electric dipole is placed at an angle of 30° with an electric field intensity 2.0 × 105 N/C. It experiences a torque equal to 4 N m. The charge on the dipole, if the dipole length is 2 cm, is :
(A) 8 mC
(B) 2 mC
(C) 5 mC
(D) 7 μC

B

Q. 22. The electric field in a certain region is acting radially outward and is given by E = Aa. A charge contained in a sphere of radius ‘a’ centred at the origin of the field, will be given by :
(A) 4πεoAa3
(B) εoAa3
(C) 4πoAa
(D) AεoAa2

A

Q. 23. A charge Q is enclosed by a Gaussian spherical surface of radius R. If the radius is doubled, then the outward electric flux will :
(A) increase four times
(B) be reduced to half
(C) remain the same
(D) be doubled

C

Q. 24. As per this diagram a point charge +q is placed at the origin O. Work done in taking another point charge −Q from the point A [co-ordinates (0, a)] to another point B [co-ordinates (a, 0)] along the straight path AB is :

(A) Zero
(B) (−qQ/4πε0×1/a2)√2a]
(C) (qQ/4πε0×1/a2)a/√2
(D) (qQ/4πε0×1/a2)√2a

A

Q. 25. A, B and C are three points in a uniform electric field. The electric potential is :

(A) Same at all the three points A, B and C
(B) Maximum at A
(C) Maximum at B
(D) Maximum at C

C

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. A parallel plate capacitor has a uniform electric field E in the space between the plates. If the distance between the plates is d and area of each plate is A, the energy stored in the capacitor is :
(D) (1/2) ε0E2

B

Q. 27. In a potentiometer of 5 wires, the balance point is obtained on the 3rd wire. To shift the balance point to the 4th wire,
(A) current of the main circuit is to be decreased.
(B) current of the main circuit is to be increased.
(C) the shifting is not possible
(D) None of the above

D

Q. 28. The electric potential at a point in free space due to a charge Q coulomb is Q × 1011 volts. The electric field at that point is :
(A) 12πε0 Q × 1022 volt/m
(B) 4πε0 Q × 1022 volt/m
(C) 12πε0 Q × 1020 volt/m
(D) 4πε0 Q × 1020 volt/m

B

Q. 29. Three capacitors each of capacity 4μF are to be connected in such a way that the effective capacitance is 6μF. This can be done by :
(A) Connecting them in parallel
(B) Connecting two in series and one in parallel
(C) Connecting two in parallel and one in series
(D) Connecting all of them in series

B

Q. 30. A capacitor of capacity C1 is charged upto V volt and then connected to an uncharged capacitor of capacity C2. Then final potential difference across each will be :
(A) C2V/(C1+C2)
(B) (1+C2/C1) × V
(C) C1V/(C1+C2)
(D) (1−C2/C1) × V

C

Q. 31. The resistance of a wire is ‘R’ ohm. If it is melted and stretched to ’n’ times its original length, its new resistance will be:
(A) R/n
(B) n2R
(C) R/n2
(D) nR

B

Q. 32. A potentiometer is an accurate and versatile device to make electrical measurements of E.M.F. because the method involves:
(B) a condition of no current flow through the galvanometer
(C) a combination of cells, galvanometer and resistances
(D) cells

B

Q. 33. The power dissipated in the circuit shown in the figure is 30 Watts. The value of R is:

(A) 15 Ω
(B) 10 Ω
(C) 30 Ω
(D) 20 Ω

C

Q. 34. A wire of a certain material is stretched slowly by ten percent. It new resistance and specific resistance become respectively :
(A) 1.1 times, 1.1 times
(B) 1.2 times, 1.1 times
(C) 1.21 times, same
(D) Both remain the same

C

Q. 35. A current of 3 amp. flows through the 2 Ω resistor shown in the circuit. The power dissipated in the 5 Ω resistor is :

(A) 5 watt
(B) 4 watt
(C) 2 watt
(D) 1 watt

A

Q. 36. A galvanometer has a coil of resistance 100 ohm and gives a full scale deflection for 30 mA current. If it is to work as a voltmeter of 30 volt range, the resistance required to be added will be :
(A) 900 Ω
(B) 1800 Ω
(C) 500 Ω
(D) 1000 Ω

A

Q. 37. A galvanometer having a coil resistance of 60 Ω shows full scale deflection when a current of 1.0 A passes through it. It can be converted into an ammeter to read currents upto 5.0 A by :
(A) putting in series a resistance of 15 Ω
(B) putting in series a resistance of 240 Ω
(C) putting in parallel a resistance of 15 Ω
(D) putting in parallel a resistance of 240 Ω

C

Q. 38. An electron is moving in a circular path under the influence of a transverse magnetic field of 3.57 × 10-2 T. If the value of e/m is 1.76 × 1011 C/kg, frequency of revolution of the electron is :
(A) 1 GHz
(B) 100 MHz
(C) 62.8 MHz
(D) 6.28 MHz

A

Q. 39. A beam of electrons is moving with constant velocity in a region having simultaneous perpendicular electric and magnetic fields of strength 20 V/m and 0.5 T respectively at right angles to the direction of motion of the electrons. Then the velocity of electrons must be :
(A) 8 m/s
(B) 20 m/s
(C) 40 m/s
(D) 1/40 m/s

C

Q. 40. A charged particle (charge q) is moving in a circle of radius R with uniform speed v. The associated magnetic moment μ is given by :
(A) qvR
(B) qvR/2
(C) qvR2
(D) qvR2/2

B

Q. 41. An iron rod of length L and magnetic moment M is bent in the form of a semicircle. Now its magnetic moment will be :
(A) M
(B) 2M/π
(C) M/π
(D) Mπ

B

Q. 42. Unit of magnetic flux density (or magnetic induction) is :
(A) Tesla
(B) Weber/metre2
(C) Newton/ampere-metre
(D) All of the above

D

Q. 43. A magnet of magnetic moment M and pole strength m is divided in two equal parts, then magnetic moment of each part will be :
(A) M
(B) M/2
(C) M/4
(D) 2M

B

Q. 44. Two coils of self inductances 2 mH and 8 mH are placed so close together that the effective flux in one coil is completely linked with the other. The mutual inductance between these coils is :
(A) 10 mH
(B) 6 mH
(C) 4 mH
(D) 16 mH

C

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): When bodies are charged through friction, there is transfer of charge from one body to another. No charge is created or destroyed.
Reason (R): This is according to the law of conservation of electric charge.

A

Q. 46. Assertion (A): If two spherical conductors of different radii have the same surface charge densities, then their electric field intensities will be equal.
Reason (R): Surface charge density = Total charge area

B

Q. 47. Assertion (A): A high resistance is connected in series with the galvanometer of meter bridge.
Reason (R): As resistance increases, the current also increases.

C

Q. 48. Assertion (A): A direct current flowing through a metallic rod produces magnetic field both inside and outside of the rod.
Reason (R): There is no flow of charge carrier inside the rod.

C

Q. 49. Assertion (A): Gauss theorem is not applicable in magnetism.
Reason (R): Magnetic monopole does not exist.

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 220 volt input is supplied to a transformer. The output circuit draws a current of 2.0 ampere at 440 volts. If the efficiency of the transformer is 80% the current drawn by the primary windings of the transformer is :
(A) 3.6 ampere
(B) 2.8 ampere
(C) 2.5 ampere
(D) 5.0 ampere

D

Q. 51. What is the value of inductance L for which the current is a maximum in a series LCR circuit with C = 10 μF and ω = 1000/s?
(A) 10 mH
(B) 100 mH
(C) 1 mH
(D) cannot be calculated unless R is known

B

Case Study

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

Types of resistors
Most common type of resistor is Carbon Composition Resistors. Carbon resistors are a cheap, general purpose resistor used in electrical and electronic circuits. Their resistive element is manufactured from a mixture of finely ground carbon dust or graphite and a non-conducting ceramic powder to bind it all together.
The ratio of carbon dust to ceramic (conductor to insulator) determines the resistive value of the resistor. Higher the ratio of carbon, lower the overall resistance.
Film Type Resistors consist of Metal Film, Carbon Film and Metal Oxide Film .Such resistors are generally made by depositing pure metals, such as nickel, or an oxide film, such as tin-oxide, on an insulating ceramic rod or substrate.
The resistive value of the resistor is controlled by increasing the desired thickness of the deposited film giving them the names of either “thick-film resistors” or “thin-film resistors”.
Film type resistors can achieve much higher ohmic value compared to other types.
Another type of resistor, called a Wirewound Resistor, is made by winding a thin metal alloy wire (Nichrome) or similar wire on an insulating ceramic former in the form of a spiral helix.
These types of resistors are generally only available in very low ohmic value with high precision.
They are able to handle much higher electrical currents than other resistors of the same ohmic value with much excessive power ratings. These high power resistors are moulded into an aluminium heat sink body with fins attached to increase their overall surface area to promote heat loss and cooling.

Q. 52. Carbon composition resistors are made from a mixture of
(A) finely ground metal dust and ceramic powder.
(B) finely ground carbon dust or graphite and ceramic powder.
(C) finely ground carbon dust or graphite and copper powder.
(D) finely ground carbon dust or graphite.

B

Q. 53. In carbon composition resistors, ______ the ratio of carbon, _____ the overall resistance.
(A) Higher, lower
(B) Lower, higher
(C) Lower, lower
(D) Higher, higher

A

Q. 54. Metal Film Type Resistors are generally made by depositing pure ______, on ______ rod or substrate.
(A) Ceramic, metal
(B) Carbon, ceramic
(C) Metal, ceramic
(D) Carbon, metal