- Amoving in a circular orbit
- Bmoving with a constant velocity
- Cfalling in an electric field
- DBoth (a) and (c)
Explanation:
An accelerated charge is the source of electromagnetic waves (EMWs). When the charge is in a circular motion, the direction of its velocity continuously changes and thus it is in accelerated motion and produces EMWs. A charge falling in an electric field is accelerated by the electric force and thus produces EMWs.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Ratio between total intensity of magnetic field at equator to poles is
| (a) 1 : 1 | (b) 1 : 2 | (c) 2 : 1 | (d) 1 : 4 |
The magnetic field due to the earth is closely equivalent to that due to
|
(a) A large magnet of length equal to the diameter of the earth |
| (b) A magnetic dipole placed at the centre of the earth |
| (c) A large coil carrying current |
| (d) Neither of the above |
A convex lens is made of a material having refractive index 1.2. Both the surfaces of the lens are convex. If it is dipped into water $(\mu=1.33),$ it will behave like:
The refractive index of water is 1.33. What will be the speed of light in water
|
(a) 3 |
(b) 2.25 |
(c) 4 |
(d) 1.33 |
In a junction diode, the holes are due to
| (a) Protons | (b) Neutrons | (c) Extra electrons | (d) Missing of electrons |
The X-ray beam coming from an X-ray tube will be
| (a) Monochromatic |
|
(b) Having all wavelengths smaller than a certain maximum wavelength |
|
(c) Having all wavelengths larger than a certain minimum wavelength |
|
(d) Having all wavelengths lying between a minimum and a maximum wavelength |
A conducting square loop of side l and resistance R moves in its plane with a uniform velocity v perpendicular to one of its sides. A magnetic induction B constant in time and space, pointing perpendicular and into the plane at the loop exists everywhere with half the loop outside the field, as shown in figure. The induced e.m.f. is

|
(a) Zero |
(b) RvB |
(c) VBl/R |
(d) VBl |