
- Is increased.
- Is decreased.
- Remains unchanged.
- Remains zero.

Explanation:

The flux of the electric field through the closed surface is remain unchanged.
Because the no. of electric field lines enter in the closed path = no. of electric field lines existsin the closed path.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
A straight wire of diameter 0.5 mm carrying a current of 1 A is replaced by another wire of 1 mm diameter carrying the same current. The strength of magnetic field far away is
|
(a) Twice the earlier value |
(b) Half of the earlier value |
|
(c) Quarter of its earlier value |
(d) Unchanged |
To explain his theory, Bohr used
|
(a) Conservation of linear momentum |
|
(b) Conservation of angular momentum |
|
(c) Conservation of quantum frequency |
|
(d) Conservation of energy |
A transformer is employed to reduce 220 V to 11 V. The primary draws a current of 5 A and the secondary 90 A. The efficiency of the transformer is
|
(a) 20% |
(b) 40% |
(c) 70% |
(d) 90% |
The approximate wavelength of a photon of energy 2.48 eV is
|
(a) 500 Å |
(b) 5000 Å |
(c) 2000 Å |
(d) 1000 Å |
An electron and a proton enter region of uniform magnetic field in a direction at right angles to the field with the same kinetic energy. They describe circular paths of radius and
respectively. Then
|
(a) |
|
(b) |
|
(c) |
|
(d) |
Half-life is measured by
|
(a) Geiger-Muller counter |
(b) Carbon dating |
|
(c) Spectroscopic method |
(d) Wilson-Cloud chamber |