Home
Class 12
PHYSICS
The anode voltage of a photocell is kept...

The anode voltage of a photocell is kept fixed. The wavelength of the light falling on the cathode is gradually changed. The plate current I of the potential varies as

A

B

C

D

Text Solution

Verified by Experts

The correct Answer is:
A
Promotional Banner

Similar Questions

Explore conceptually related problems

The stopping potential in a photoelectric experiment is linearly related to the inverse of the wavelength (1/lambda) of the light falling on the cathode. The potential difference applied across an X-ray tube is linearly related to the inverse of the cutoff wavelength (1/lambda) of the X-ray emitted. Show that the slopes of the lines in the two cases are equal and find its value.

Find the thickness of a plate which will produce a change in optical path equal to half the wavelength lamda of the light passing through it normally. The refractive index of the plate is mu .

A small metal plate of work function phi is kept at a distance r from a singly ionised, fixed ion. A monochromatic light beam is incident on the metal plate and photoelectrons are emitted. Find maximum wavelength of the light beam so that some of that electrons may go round the ion along a circle.

A silver ball of radius 4.8 cm is suspended by a thread in a vacuum chamber, Ultraviolet light of wavelength 200nm is incident on the ball for some time during which a total light energy of 1.0 xx 10^-7 J falls on the surface. Assuming that on the average one photon out of every ten thousand is able to eject a photoelectron, find the electric potential at the surface of the ball assuming zero potential at infinity. What is the potential at the centre of the ball?

The plate resistance and the amplification factor of a triode are 10 kOmega and 20 . The tube is operated at plate voltage 250 V and grid voltage -7.5 V . The plate current is 10 mA . (a) To what value should the grid voltage be changed so as to increase the plate current to 15 mA ? (b) To what value should the plate voltage be changed to take the plate current back to 10 mA ?

The plate resistance of a triode is 8 kOmega and the transconductance is 2.5 millimho . (a)If the plate voltage is increased by 48 V , and the grid voltage is kept constant, what will be the increase in the plate current? (b) With plate voltage kept constant at this increased value, how much should the grid voltage be decreased in order to bring the plate current back to its initial value?

The dynamic plate resistance of a triode valve is 10 kOmega . Find the change in the plate current if the plate voltage is changed from 200 V to 220 V .

Light is incident on the cathode of a photocell and the stopping voltages are measured for light of two different wavelengths, are given below. a. Determine the work function of the metal of the cathode in eV. b. Find the value of the universal constant (hc)/(e ) . c. Define stopping potential and work function. d. Can you suggest a mathematical relation between kinetic energy and stopping potential?

A certain metallic surface is illuminated with manochromatic light of wavelength , lambda . The stopping potential for photoelectric current for this light is 3V_0 . If the same surface is illuminated with light of wavelength 2lambda , the stopping potential is V_0 . The threshold wavelength for this surface for photoelectric effect is: