- APhotodiodes
- BSolar cells
- CLight emitting diodes
- DAll of the above
Explanation:
P-n junctions are an integral part of several optoelectronic devices. These include photodiodes, solar cells light emitting diodes (LEDs) and semiconductor lasers.
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The electrochemical equivalent of a metal is 3.3
. The mass of the metal liberated at the cathode when a 3 A current is passed for 2 seconds will be
|
(a) |
(b) 9.39 |
(c) 6.6 |
(d) 1.1 |
A simple pendulum with bob of mass m and conducting wire of length L swings under gravity through an angle 2θ. The earth’s magnetic field component in the direction perpendicular to swing is B. Maximum potential difference induced across the pendulum is

|
(a) 2BL sin |
(b) BL sin |
|
(c) BL sin |
(d) 2BL sin |
Two batteries A and B each of e.m.f. 2 V are connected in series to an external resistance R = 1 ohm. If the internal resistance of battery A is 1.9 ohms and that of B is 0.9 ohm, what is the potential difference between the terminals of battery A
|
(a) 2 V |
(b) 3.8 V |
(c) Zero |
(d) None of the above |
An electric dipole consisting of two opposite charges of 2 each separated by a distance of 3 cm is placed in an electric field of 2
N/C. The maximum torque on the dipole will be
|
(a) 12 |
(b) 12 |
(c) 24 |
(d) 24 |
The relation between dynamic plate resistance (rp) of a vacuum diode and plate current in the space charge limited region, is
|
(a) |
(b) |
(c) |
(d) |
An atom of mass number 15 and atomic number 7 captures an α - particle and then emits a proton. The mass number and atomic number of the resulting product will respectively be
|
(a) 14 and 2 |
(b) 15 and 3 |
(c) 16 and 4 |
(d) 18 and 8 |
The true statement for thermo e.m.f. of a thermocouple
|
(a) Depends on the nature of metals |
|
(b) Depends only on temperature of cold junction |
|
(c) Depends only on temperature of hot junction |
|
(d) Depends on the length of the wires used for thermocouple |