MODEL PAPER 1 — Physics STD 12 Science — Question

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): Total energy of revolving electron in any stationary orbit is negative.
Reason (R): Energy is a scalar quantity. It can have positive or negative value.

Assertion (A): A bulb connected in series with a solenoid is connected to ac source. If a soft iron core is introduced in the solenoid, the bulb will glow brighter.
Reason (R): On introducing soft iron core in the solenoid, the inductance increases.

Assertion : For a charged particle moving from point P to point Q, the net work done by an electrostatic field on the particle is independent of the path connecting point P to point Q.
Reason : The net work done by a conservative force on an object moving along a closed loop is zero.

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): ln YDSE bright and dark fringe are equally spaced.
Reason (R): It only depends upon phase difference.

Two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from thecodes(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 ratio of free electrons to holes in intrinsic semiconductor is greater than one.
Reason: The electrons are lighter particles and holes are heavy particles.

Two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from thecodes(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 depletion layer in the p-n junction is free from mobile charge carriers.
Reason: There is no electric field across the junction barrier.

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): A narrow pulse of light is sent through a medium. The pulse will retain its shape as it travels through the medium.
Reason (R): A narrow pulse is made of harmonic waves with a large range of wavelengths.

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 electromagnetic waves are transverse in nature.
Reason: These waves propagate in straight lines.

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 Rare 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): Acceleration of a magnet falling through a copper ring decreases.
Reason (R): The induced current produced in a circuit always flow in such direction that it opposes the change or the cause that produced it.