Download App

Ray Optics and Optical Instruments — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsRay Optics and Optical Instruments1 Mark
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: The minimum distance between an object and its real image formed by a convex lens is 2f.
Reason: The distance between an object and its real image is minimum when its magnification is two.
✓

Answer

  1. A is false and R is also false.
Explanation:

The distance between the object and its real image is minimum when magnification is I. We know that the magnification of convex lens is given by $\text{m}=-\frac{\text{v}}{\text{u}}$ for m = 1, v = -u.

Now from lens formula, v = u = 2f

Hence, minimum distance v + u = 4f.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Assertion (A) & Reason (B) MCQ" from Ray Optics and Optical Instruments→Ray Optics and Optical Instruments — all question types→Physics STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

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.
→
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): When two coils are wound on each other, the mutual induction between the coils is maximum.
Reason (R): Mutual induction does not depend on the orientation of the coils.
→
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: At 0K, Germanium is a superconductor.
Reason: At 0K, Germanium offers zero resistance.
→
Assertion (A): Two equipotential surfaces cannot cut each other.
Reason (R): Two equipotential surfaces cannot cut each other.
→
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.
→
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 (A): Range of Coulomb force is infinite.
Reason (R): Coulomb force acts between two charged 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 resistance of p-n junction is low when forward biased and is high when reverse biased.
Reason: In reversed biased, the depletion layer is reduced.
→
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 current is represented by a straight line, the magnetic field will be circular.
Reason (R): According to Fleming's left hand rule, direction of force is parallel to the magnetic field.
→
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): The earth's magnetic field is due to iron present in its core.
Reason (R): At a low temperature magnet losses its magnetic property or magnetism.
→
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): It is essential that all the lines available in the emission spectrum will not be available in the absorption spectrum.
Reason (R): The spectrum of hydrogen atom is only absorption spectrum
→