Explanation:
Force will decreases because when medium is inserted between then it will reduces the forces by its permitivity. the force becomes
$\text{Fe}_\text{m}=\frac{\text{Fe}}{\in_\text{r}}$
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
As a result of interference of two coherent sources of light, energy is
|
(a) Increased |
|
(b) Redistributed and the distribution does not vary with time |
|
(c) Decreased |
|
(d) Redistributed and the distribution changes with time |
The speed of electromagnetic wave in vacuum depends upon the source of radiation
|
(a) Increases as we move from g-rays to radio waves |
|
(b) Decreases as we move from g-rays to radio waves |
|
(c) Is same for all of them |
|
(d) None of these |
At a certain place a magnet makes 30 oscillations per minute. At another place where the magnetic field is double, its time period will be
| (a) 4 sec | (b) 2 sec |
(c) 
|
(d) 
|
Wavefront of a wave has direction with wave motion
|
(a) Parallel |
(b) Perpendicular |
(c) Opposite |
(d) At an angle of 𝜃 |
A person's near point is 50 cm and his far point is 3 m. Power of the lenses he requires for
(i) reading and (ii) for seeing distant stars are
|
(a) – 2 D and 0.33 D |
(b) 2 D and – 0.33 D |
(c) – 2 D and 3 D |
(d) 2 D and – 3 D |
A parallel plate condenser is immersed in an oil of dielectric constant 2. The field between the plates is
|
(a) Increased proportional to 2 |
(b) Decreased proportional to |
|
(c) Increased proportional to |
(d) Decreased proportional to |
