Explanation:
Justification of (a) and (b):
Investigators and experimenters have failed to find any sign of magnetic monopoles. So, we can assume that magnetic monopoles are only a mathematical assumption.
A magnetic field is produced by the motion of an electric charge only. In paramagnets or ferromagnets, the motion of an electron (charge) and the alignment of domains (bunch of charges with particular alignment) create paramagnetism and ferromagnetism, respectively.
Therefore, the only cause behind the magnetic field is the motion of an electric charge.
Denial of (c):
The north pole is equivalent to an anticlockwise current and the south pole is equivalent to a clockwise current.
Denial of (d):
A bar magnet is not equivalent to a long, straight current because the distribution and orientation of magnetic field lines do not resemble each other.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
A 100 ohm galvanometer gives full scale deflection at 10 mA. How much shunt is required to read 100 mA
|
(a) 11.11 ohm |
(b) 9.9 ohm |
(c) 1.1 ohm |
(d) 4.4 ohm |
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 |
There are certain types of stars called visible stars which undergo periodic change in their light output. If such a star quadruple it's light output, how much does it's magnitude change
|
(a) – 1.25 |
(b) – 1.5 |
(c) – 1.75 |
(d) – 2 |
A laser beam of pulse power 1012 watt is focussed on an object are 10–4 cm2. The energy flux in watt/ cm2 at the point of focus is
|
(a) 1020 |
(b) 1016 |
(c) 108 |
(d) 104 |