Dual nature of radiation and matter 1

Two photons, each of energy 2.5 eV are simultaneously incident on sodium metal surface the work function of sodium is 2.75 eV, then from its surface __________ will be emitted.

• one electron

• two electrons

• more than two electrons

• not a single electron

1 eV is equal to _______

When the intensity of a light source is increased

• the number of photons emitted by the source in unit time increases

• more energetic photons are emitted

• faster photons are emitted

• total energy of the photons emitted per unit time decreases

The photo current in an experiment on photoelectric effect increases if

• the intensity of the source is increased

• the exposure time is increased

• the intensity of the source is decreased

• the exposure time is decreased

As the intensity of incident light increases, the

• K.E of emitted photo electrons increases

• photoelectric current decreases

• photoelectric current increases

• K.E of emitted photo electrons decreases

The value of stopping potential when the frequency of light is equal to the threshold frequency is

• maximum

• zero

• minimum

• infinity

Light exhibits ______ duality

• particle-wave

• solid-liquid

• liquid-gas

• gas-plasma

The phenomenon by which metals emit electrons under the influence of radiation is called ____

• photoelectric effect

• interference

• polarization

• ionization

Photoelectric effect was first discovered by

• Einstein

• Newton

• Hertz

• Germer

At the stopping potential, photoelectric current is _______-

• maximum

• a constant

• zero

• infinity