Nuclei — Physics STD 12 Science — Question

When the energy of the incident radiation is increased by 20%, the kinetic energy of the photoelectrons emitted from a metal surface increased from 0.5eV to 0.8eV. The work function of the metal is?

When a charged particles moves in a uniform magnetic field in a direction perpendicular to the field, then the path of the particle will be:

Demagnetisation of magnets can be done by

(a) Rough handling	(b) Heating
(c) Magnetising in the opposite direction	(d) All the above

In a charge free region, electric field lines can be taken to be continuous curves:

Lenz's law is a direct consequence of:

The example for non-ohmic resistance is

(a) Copper wire

(b) Carbon resistance

(c) Diode

(d) Tungston wire

An object of height 1.5 cm is placed on the axis of a convex lens of focal length 25 cm. A real image is formed at a distance of 75 cm from the lens. The size of the image will be

(a) 4.5 cm

(b) 3.0 cm

(c) 0.75 cm

(d) 0.5 cm

In series combination of capacitors the effective capacitance:

For harder X-rays: