MODEL PAPER 10 — Physics STD 12 Science — Question

For question, statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a) (b) (c) and (d) as given below.

1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is NOT the correct explanation of A.
3. A is true, but R is false.
4. A is false and R is also false.

Assertion (A): A fission reaction can be more easily controlled than a fission reaction.
Reason (R): The percentage of mass converted to energy in a fission reaction is 0.1% whereas in a fission reaction it is 0.4%

Two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is NOT the correct explanation of A.
3. A is true but R is false.
4. A is false and R is also false.

Assertion (A): When the observation point lies along the length of the current element, magnetic field is zero.
Reason (R): Magnetic field close to current element is zero.

Directions: In the following questions, the Assertions (A) and Reason(s) (R) have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion: χ - T graph for a diamagnetic material is a straight line parallel to T axis.
Reason: This is because susceptibility of a diamagnetic material is not affected by temperature

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
3. Assertion is correct but Reason is incorrect.
4. Both Assertion and Reason are incorrect.

For question two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is NOT the correct explanation of A.
3. A is true but R is false.
4. A is false and R is also false.

Assertion (A): In Young's double slit experiment, the fringes become indistinct ifone of the slits is covered with cellophane paper.
Reason (R): The cellophane paper decrease the wavelength of light.

Two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false and R is also false.

Assertion: Optical fibers are used to transmit light without any loss in its intensity over distance of several kilometers.
Reason: Optical fibers are very thick and all the light is passed through it without any loss.

For two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is not the correct explanation of A.
3. A is true, but R is false.
4. A is false, and R is also false.

Assertion: The temperature coefficient of resistance is always positive only for metals.
Reason: On increasing the temperature, the resistance of metals and alloys increases.

Two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false and R is also false.

Assertion: Light is a transverse wave but not an electromagnetic wave.
Reason: Maxwell showed that speed of electromagnetic waves is related to the permittivity of the medium through which it travels.

Assertion: Positive charge always moves from a higher potential point to a lower potential point.
Reason: Electric potential is a vector quantity.

Assertion (A) : Light added to light can produce darkness.
Reason (B) : When two coherent light waves interfere, there is darkness at position of destructive interference.

For question two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions front the codes (a), (b), (c) and (d) as given below.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is NOT the correct explanation of A.
3. A is true but R is false.
4. A is false and R is also false.

Assertion (A): On increasing the frequency of light, larger number of photoelectrons are emitted.
Reason (R): The number of electrons emitted is directly proportional to the intensity of incident light.