Atoms — Physics STD 12 Science — Question

In a Young's double slit experiment, the slits are 2 mm apart and are illuminated with a mixture of two wavelength   and λ = 900 nm. The minimum distance from the common central bright fringe on a screen 2m  from the slits where a bright fringe from one interference pattern coincides with a bright fringe from the other is

(a) 1.5 mm

(b) 3 mm

(c) 4.5 mm

(d) 6 mm

Equivalence in the following circuit is:

 Maxwell in his famous equations of electromagnetism introduced the concept of:

For the nuclie with mass number > 100:

When a current passes through a wire whose different parts are maintained at different temperatures, evolution or absorption of heat all along the length of wire is known as

(a) Joule effect

(b) Seebeck effect

(c) Peltier effect

(d) Thomson effect

A 20 cm length of a certain solution causes right-handed rotation of 38°. A 30cm length of another solution causes left-handed rotation of 24°. The optical rotation caused by 30cm length of a mixture of the above solutions in the volume ratio 1 : 2 is

(a) Left handed rotation of 14°	(b) Right handed rotation of 14°
(c) Left handed rotation of 3°	(d) Right handed rotation of 3°

The magnitude of the electric field is given by the change in magnitude of potential per unit displacement _____ to the equipotential surface at the point.

The properties of a surface are different from those of the bulk liquid because the surface molecules:

1. Are smaller than other molecules.
2. Acquire charge due to collision from air molecules.
3. Find different type of molecules in their range of influence.
4. Feel a net force in one direction.

The current through choke coil increases form zero to 6A in 0.3 seconds and an induced e.m.f. of 30 V is produced. The inductance of the coil of choke is

(a) 5 H

(b) 2.5 H

(c) 1.5 H

(d) 2 H

When the N-pole of a bar magnet points towards the south and S-pole towards the north, the null points are at the

(a) Magnetic axis	(b) Magnetic centre
(c) Perpendicular divider of magnetic axis	(d) N and S poles