Nuclei — Physics STD 12 Science — Question

A rubber balloon is given a charge Q distributed uniformly over its surface. Is the field inside the balloon zero everywhere if the balloon does not have a spherical surface?

How does the angle of minimum deviation of a glass prism vary, if the incident violet light is replaced by red light? Give reason.

A diverging lens of focal length 20cm and a converging mirror of focal length 10cm are placed coaxially at a separation of 5cm. Where should an object be placed so that a real image is formed at the object itself?

If the intensity of incident radiation is increased in a photoelectric cell, how will the stopping potential change?

Which part of electromagnetic spectrum has highest frequency?

A gas is kept in an enclosure. The pressure of the gas is reduced by pumping out some gas. Will the temperature of the gas decrease by Charles's law?

Drift velocity is inversely proportional to what? and it does not depend on what?

Write the relation between threshold frequency and work function.

Mark the correct options.

1. The luminous efficiency of a monochromatic source is always greater than that of a white light source of same power.
2. The luminous efficiency of a monochromatic source of wavelength 555nm is always greater than that of a white light source of same power.
3. The illuminating power of a monochromatic source of wavelength 555nm is always greater than that of a white light source of same power.
4. The illuminating power of a monochromatic source is always greater than that of a white light source of same power.