Assertion : The de Broglie wavelength of an electron accelerated through 941 volts is 0.4 Å.

Question

Direction Read the following question choose if: 

(a) Both Assertion and Reason are true and Reason is correct explanation of Assertion. 

(b) Both Assertion and Reason are true, but Reason is not correct explanation of Assertion. 

(c) Assertion is true but the Reason is false. 

(d) Both Assertion and Reason is false. 

Assertion : The de Broglie wavelength of an electron accelerated through 941 volts is 0.4 Å. 

Reason : Higher the acceleration potentials of electron, smaller is the de Broglie wavelength. 

(A) a 

(B) b 

(C) c 

(D) d

Answer 1

The correct option is (B) b.

Explanation:

For electron, λ = [{12.27} / √V] Å 

Hence λ = {(12.27) / √(941)} = 0.4 Å 

Also λ ∝ (1 / √V) where is accelerating potential is V. if V is higher, λ is smaller. Hence both statements are true but reason not correct explanation of assertion.