- AIts radius decreases
- BIts radius increases
- CThe bubble collapses
- DNone of these
Explanation:
The radius of soap bublle increases because of outward force acting on the bubble due to charging.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

The magnetic moment of a current carrying loop is 2.1
. The magnetic field at a point on its axis at a distance of 1
is
|
(a) 4.2 |
(b) 4.2 |
|
(c) 4.2 |
(d) 4.2 |
A short bar magnet placed with its axis at 30° with a uniform external magnetic field of 0.16 Tesla experiences a torque of magnitude 0.032 Joule. The magnetic moment of the bar magnet will be
|
(a) 0.23 Joule/Tesla |
(b) 0.40 Joule/Tesla |
(c) 0.80Joule/Tesla |
(d) Zero |
Select the correct alternative, The angle between the normal and refracted ray is called:
A point source of light is placed 4 m below the surface of water of refractive index 5 / 3. The minimum diameter of a disc which should be placed over the source on the surface of water to cut–off all light coming out of water is
|
(a) 2 m |
(b) 6 m |
(c) 4 m |
(d) 3 m |
$\text{p}=0,\text{ E}\neq0$
$\text{p}\neq0,\text{ E}=0$
$\text{p}\neq0,\text{ E}\neq0$
$\text{p}=0,\text{ E}=0$
For production of characteristic
X-rays, the electron transition is
|
(a) n = 2 to n = 1 |
(b) n = 3 to n = 2 |
(c) n = 3 to n = 1 |
(d) n = 4 to n = 2 |