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?
de Broglie wavelength of an electron
where 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 will decrease.
Angular width of the central maximum is where a is the width of slit.
If decreases, will decrease
Therefore, the correct statement is (a).