Solution:
With increase in temperature, the number density of current carries increases, relaxation time decreases but effect of decrease in relaxation is much less than increase in number density. So, the conductivity of a semiconductor increases with increase in temperature.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Two spherical conductors B and C having equal radii and carrying equal charges in them repel each other with a force F when kept apart at some distance. A third spherical conductor having same radius as that of B but uncharged is brought in contact with B, then brought in contact with C and finally removed away from both. The new force of repulsion between B and C is
|
(a) F/4 |
(b) 3F/4 |
(c) F/8 |
(d) 3F/ 8 |
A light source approaches the observer with velocity 0.8 c. The doppler shift for the light of wavelength 5500 Å is
|
(a) 4400 Å |
(b) 1833 Å |
(c) 3167 Å |
(d) 7333 Å |
Point charge 
and 
are kept at points x = 0 and x = 6 respectively. Electrical potential will be zero at points
|
(a) x = 2 and x = 9 |
(b) x = 1 and x = 5 |
(c) x = 4 and x = 12 |
(d) x = -2 and x = 2 |