- AA ferromagnetic material becomes paramagnetic.
- BA paramagnetic material becomes diamagnetic.
- CA ferromagnetic material becomes diamagnetic.
- DA paramagnetic material becomes ferromagnetic.
Explanation:
Curie Tempearture is the temperature at which certain materials lose their permanent magnetic properties, to be replaced by induced magnetism. In other words, it is the temperature above which a ferromagnetic material becomes paramagnetic.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
White light is passed through a prism whose angle is 5°. If the refractive indices for rays of red and blue colour are respectively 1.64 and 1.66, the angle of deviation between the two colours will be
|
(a) 0.1 degree |
(b) 0.2 degree |
(c) 0.3 degree |
(d) 0.4 degree |
Two galvanometers A and B require 3mA and 5mA respectively to produce the same deflection of 10 divisions. Then
|
(a) A is more sensitive than B |
(b) B is more sensitive than A |
|
(c) A and B are equally sensitive |
(d) Sensitiveness of B is 5/3 times that of A |
Three charges Q(+q) and (+q) are placed at the vertices of an equilateral triangle of side l as shown in the figure. If the net electrostatic energy of the system is zero, then Q is equal to
|
(a) |
(b) (-q) |
(c) (+q) |
(d) Zero |
Which of the following spectral series in hydrogen atom give spectral line of 4860 Å
|
(a) Lyman |
(b) Balmer |
(c) Paschen |
(d) Brackett |
Half life of a radio-active substance is 20 minutes. The time between 20% and 80% decay will be
|
(a) 20 minutes |
(b) 40 minutes |
(c) 30 minutes |
(d) 25 minutes |