Dual Nature of ...

Assertion Photo sensitivity of a meal is high if its work function is small.
Reason Work function = hf₀ where f₀ is the threshold frequency.

Assertion The de-Broglie wavelength of a molecule varies inversely as the square root of temperature.
Reason The root mean square velocity of the molecule depends on the temperature.

Assertion An electron is not deflected on passing through certain region of space. This observation confirms that there is no magnetic field in that region.
Reason The deflection of electron depends on angle between velocity of electron and direction of magnetic field.

Assertion Electric conduction in gases is possible at normal pressure.
Reason The electric conduction in gases depends only upon the potential difference between the electrodes.

Assertion Light is produced in gases in the process of electric discharge through them at high pressure.
ReasonAt high pressure electrons of gaseous atoms collide and reach and excited state.

Assertion The photo electrons produced by a monochromatic light beam incident on a metal surface have a spread in their kinetic energies.
Reason The work function of the metal varies as a function of depth from the surface.

Assertion An electric field is preferred in comparison to magnetic field for detecting the electron beam in a television picture tube.
Reason Electric field requires low voltage.

Assertion The specific charge for positive rays is a characteristic constant.
Reason The specific charge depends on charge and mass of positive ions present in positive rays.

Assertion In Millikan\'s experiment for the determination of charge on an electron, oil drops of any size can be used.
Reason Millikan\'s experiment determines the charge on electron, by simply measuring the terminal velocity.

Assertion In the process of photoelectric emission, all the emitted photo electrons have the same kinetic energy.
Reason The photon transfers its whole energy to the electron of the atom in photoelectric effect.