MOVING CHARGES AND MAGNETISM — Physics STD 12 Science — Question

A photographic film is coated with a silver bromide layer. When light fells on this film, silver bromide molecules dissociate end the film records the light there. A minimum of 0.6eV is needed to dissociate a silver bromide molecule. Find the maximum wavelength of light that can be recorded by the film.

A Galilean telescope is 27cm long when focused to form an image at infinity. If the objective has a focal length of 30cm, what is the focal length of the eyepiece?

A spherical conducting shell of inner radius r₁ and outer radius r₂ has a charge ‘Q’. A charge ‘q’ is placed at the centre of the shell.

1. What is the surface charge density on the (i) inner surface, (ii) outer surface of the shell?
2. Write the expression for the electric field at a point x > r₂ from the centre of the shell.

What are the (a) momentum, (b) de-Broglie wavelength of an electron with kinetic energy of 120 eV. ? Find.

A sphere of radius 5 cm has a charge of 31.41 µC. Calculate the surface density of charge.

"The total energy of the electron in the hydrogen atom is negative." What does this fact indicate? If the total energy of the electron was positive than what result will have been achieved?

Any current flowing through a copper wire when passed through an iron wire of same thickness. What will be the effect on its drift velocity?

Verify that the units weber and volt-second are the same.

Explain how the mass of an electron can be found using Millikan's oil drop experiment.