X-rays are not used for radar purpose because

X-rays were discovered by

In radio theraphy, X-rays are used to

The light rays having photons of energy 1.8 eV are falling on a metal surface having a work function 1.2 eV. What is the stopping potential to be applied to stop the emitting electrons

The velocity of photon is proportional to (where n is frequency)

Consider the two following statements A and B and identify the correct choice given in the answers;
A) In photovlotaic cells the photoelectric current produced is not proportional to the, intensity of incident light.
B) In gas filled photoemissive cells, the velocity of photoelectrons depends on the wavelength of the incident radiation.

If the function is continuous at x= then k equals

The function has

In the, following compounds, the order of basicity is :
I)
II)
III)
IV)

Arrange the following carbocations in decreasing order of stability:
I)
II)
III)
IV) 

If and where exists, then is continuous on

The value of f (0) so that the function is continuous at  is

For such questions, we should know formula for different limits.

Light of two different frequencies whose photons have energies and respectively, successively illuminates a metal of work function . The ratio of maximum kinetic energy of the emitted electron will be

4 eV is the energy of the incident photon and the work function in What is the stopping potential

The work functions for sodium and copper are and . Which of them is suitable for a photocell with 4000 light

When yellow light is incident on a surface, no electrons are emitted while green light can emit. If red light is incident on the surface, then