If the wavelength of light in an experiment on photoelectric effect is doubled,
(i) the photoelectric emission will not take place
(ii) the photoelectric emission may or may not take place
(iii) the stopping potential will increase
(iv) the stopping potential will decrease

Options

A. the photoelectric emission will not take place.
B. the photoelectric constant emission may or may not take place
C. the stopping potential will decreases
D. the stopping potential will increases

Answer

b,c

Explanation

As `K=eV_(0)=(hc)/(lambda)-phi_(0)`. If `lambda` becomes double, then, `K'=eV'_(0)=(hc)/(2lambda)-phi_(0)`. If the value of `(hc)/(2lambda) gt phi_(0)`, emission of photoelectrons will take place. If `(hc)/(2lambda) lt phi_(0)`, no photoelectric emission will take place. The increases in wavelength will decreases the stopping potential as `V_(0)prop1/lambda`