Download App

Wave Optics — Physics STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 SciencePhysicsWave Optics1 Mark
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): When a tiny circular obstacle is placed in the path of light from a distant source, a bright spot is seen at the centre of the shadow of the obstacle.
Reason (R): Wave diffracted from the edges of circular obstacle interfere constructively at the centre of the shadow resulting in the formation of bright spot.
✓

Answer

  1. Both A and R are true and R is the correct explanation of A.
Explanation:
Point of constructive interference or maxima is obtained when path difference between the two interfering waves is an integral multiple of wavelength.

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 Wave Optics→Wave Optics — all question types→Physics STD 12 Science question papers→Rajasthan Board STD 12 Science question papers→Rajasthan Board question paper generator→

Similar questions

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.
Assertion $(A):$ A tube light emits white light
Reason $(R):$ Emission of light in a tube takes place at a very high temperature.
→
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 absolute zero the conductivity of semiconductor is zero.
Reason: In a semiconductor there are no free electrons at any temperature.
→
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): Work function of aluminium is 4.2eV. Emission of electrons will not be possible if two photons each of energy 2.5eV strike an electron of aluminium.
Reason (R): For photoelectric emission the energy of each photon should be greater than the work function of aluminium.
→
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: Capacitor serves as a block for D.C. and offers an easy path to A.
Reason: Capacitive reactance is inversely proportional to frequency.
→
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: Step-down transformer increases the current.
Reason: Transformer obeys the law of conservation of energy.
→
Assertion (A): Positive charge always moves from a higher potential point to a lower potential point. 
Reason (R): Electric potential is a vector quantity.
→
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: Substances which at room temperature retain their ferromagnetic property for a long period of time are called permanent magnets.
Reason: Permanent magnet can be made by placing a ferromagnetic rod in a solenoid and passing current through it.
  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.
→
Assertion  (A): If the distance between parallel plates a capacitor is halved and dielectric constant is made three times then the capacitance becomes six times.
Reason (R) : Capacitance of the capacitor does not depend upon the nature of the material of the plates of the capacitor.
→
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: Diode lasers are used as optical sources in optical communicatiod.
Reason: Diode lasers consume less energy.
→
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): A small metal ball is suspended in a uniform electric field with an insulated thread. If high-energy X-ray beam falls on the ball, the ball will be deflected in the electric field.
Reason (R): X-rays emits photoelectron and metal becomes negatively charged.
→