Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

A space or region around a magnet in which a force is experienced by magnetic pole is called.

Two plates are at potentials –10 V and +30 V. If the separation between the plates be 2 cm. The electric field between them is

(a) 2000 V/m

(b) 1000 V/m

(c) 500 V/m

(d) 3000 V/m

The radius of a nucleus of a mass number A is directly proportional to

(a)

(b) A

(c)

(d)

If a proton and electron have same de Broglie wavelength, then:

A capacitor is charged by a battery. The battery is removed, and another identical uncharged capacitor is connected in parallel. The total electrostatic energy of resulting system.

A circular disc of which 2/3 part is coated with yellow and 1/3 part is with blue. It is rotated about its central axis with high velocity, then it will be seen as

(a) Green

(b) Brown

(c) White

(d) Violet

A dip circle is taken to geomagnetic equator. The needle is allowed to move in a vertical plane perpendicular to the magnetic meridian. The needle will stay:

The equivalent energy to 1 amu is :

There are two metallic spheres of same radii, but one is solid, and the other is hollow, then:

The Bohr radius of the fifth electron of phosphorus (atomic number = 15) acting as dopant in silicon (relative dielectric constant = 12) is

(a) 10.6 Å

(b) 0.53 Å

(c) 21.2 Å

(d) None of these