Question

GaAs is

(a) Element semiconductor

(b) Alloy semiconductor

(c) Bad conductor

(d) Metallic semiconductor

Answer

(b) Alloy semiconductor

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

The absorption transitions between the first and the fourth energy states of hydrogen atom are 3. The emission transitions between these states will be    

(a) 3 

(b) 4

(c) 5  

(d) 6

A voltmeter has resistance of 2000 ohms and it can measure upto 2V. If we want to increase its range to 10 V, then the required resistance in series will be

(a) 2000 Ω

(b) 4000  Ω

(c) 6000 Ω

(d) 8000 Ω

The time of revolution of an electron around a nucleus of charge Ze in nth Bohr orbit is directly proportional to

(a) n 

(b)  

(c)

(d)

Pure inductance of 3.0 H is connected as shown below. The equivalent inductance of the circuit is

(a) 1 H

(b) 2 H

(c) 3 H

(d) 9 H

The photoelectric effect was successfully explained by

Assertion  :  Two P-N junction diodes placed back to back, will work as a NPN transistor.

Reason     : The P-region of two PN junction diodes back to back will form the base of NPN transistor.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c) If assertion is true but reason is false.

(d) If the assertion and reason both are false.

If intensity of incident light is increased in PEE then which of the following is true

(a) Maximum K.E. of ejected electron will increase

(b) Work function will remain unchanged

(c) Stopping potential will decrease

(d) Maximum K.E. of ejected electron will decrease

In the following figure, the magnet is moved towards the coil with a speed v and induced emf is e. If magnet and coil recede away from one another each moving with speed v, the induced emf in the coil will be

(a) e

(b) 2e

(c) e/2

(d) 4e

Two bodies A and B having equal surface areas are maintained at temperatures 10°C and 20°C. The thermal radiation emitted in a given time by A and B are in the ratio:
  1. 1 : 1.15
  2. 1 : 2
  3. 1 : 4
  4. 1 : 16
A train is moving towards north with a speed of 180 kilometers per hour. If the vertical component of the earths magnetic filed is 0.2 × 10-4 T, the emf induced in the axle of length 1.5m is