Q.

A parallel beam of fast moving electrons is incident normally on a narrow slit. A fluorescent screen is placed at a large distance from the slit. If the speed of the electrons is increased, which of the following statements is correct?

Moderate

Unlock the Full Solution and Master the Concept

Get a detailed solution and exclusive access to our masterclass to ensure you never miss a concept
By Expert Faculty of Sri Chaitanya

a

The angular width of the central maximum will decrease.

b

The angular width of the central maximum will be unaffected.

c

Diffraction pattern is not observed on the screen in the case of electrons.

d

The angular width of the central maximum of the diffraction pattern will increase.

answer is 1.

(Detailed Solution Below)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

de Broglie wavelength of an electronλ=hp=hmvwhere m is the mass and v is the speed of the electron respectively.If speed v of electron is increased, momentum p (= mv) will increase. Hence, wavelength λ will decrease.Angular width of the central maximum is θ0=2λawhere a is the width of slit.If λ  decreases, θ0 will decreaseTherefore, the correct statement is (a).
ctaimg
Choose your Grade and Exam
edit icon

Connect with our

Expert Counsellors

access to India's best teachers with a record of producing top rankers year on year.

+91

We will send a verification code via OTP.

whats app icon