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Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : Emission of electrons in photoelectric effect can be suppressed by applying a sufficiently negative electron potential to the photoemissive substance. Reason (R) : A negative electric potential, which stops the emission of electrons from the surface of a photoemissive substance, varies linearly w

Options

  1. A(A) is false but (R) is true
  2. B(A) is true but (R) is false
  3. CBoth (( A ) ) and (( R ) ) are true and (( R ) ) is the correct explanation of (( A ) )
  4. DBoth (( A ) ) and (( R ) ) are true but (( R ) ) is not the correct explanation of (( A ) )

Correct answer

D. Both (( A ) ) and (( R ) ) are true but (( R ) ) is not the correct explanation of (( A ) )

Step-by-step solution

Assertion (A) is true because a sufficiently negative potential can repel and stop the emitted electrons from leaving the surface. Reason (R) is also true because the stopping potential (V_ stop ) varies linearly with the frequency ( ) of the incident light ( (V_ stop = h e - e ) ). However, (R) does not directly explain why a negative potential suppresses electron emission; it only shows how much potential is needed for different frequencies. Therefore, both (A) and (R) are true, but (R) is not the correct explana

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