Assertion: Transistor can be used as a switch. 

Reason:  Both linear and non-linear voltage bias dependence occurs in it.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

The logic gate represented in the following figure is 

• OR gate

• NOT gate

• NAND gate

• XOR gate

Assertion:  A pure semiconductor has negative temperature coefficient of resistance.

Reason:  On raising the temperature, more charge carriers are released, conductance increases and resistance decreases.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false.

Assertion:  At a fixed temperature, silicon will have a minimum conductivity when it has a smaller acceptor doping.

Reason:  The conductivity of an intrinisic semiconductor is slightly higher than that of a lightly doped p-type

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false.

When the inputs of a two input logic gate are  0  and  0, the output is 1. When the inputs are 1 and 0, the output is zero. The type of logic gate is

• XOR

• NAND

• NOR

• OR

In  the  given  circuit,  the  potential difference  between  A  and  B  is

• 0

• 5 volt

• 10 volt

• 15 volt

Assertion:  A photocell is called an electric eye. 

Reason:  When light is incident on some semiconductor its electrical resistance is reduced.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion 

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion:  In  a  common-emitter  amplfier,  the  load  resistance  of  the  output  circuit is 1000  times  the load  resistance of  the  input  circuit. If  $\mathrm{\alpha }$ = 0.98, then  voltage  gain  is 49 x 10³.

Reason:  $\mathrm{\alpha } = \frac{\mathrm{\alpha }}{1 - \mathrm{\beta }}$ ( symbols have  their  usual  meaning ).

• If  both  assertion  and  reason  are  true  and  reason is the  correct  explanation  of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion:  Most  amplifiers  use  common  emitter  circuit configuration. 

Reason:  Its input resistance is comparatively higher.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

A  Ge specimen  is  doped with Al. The concentration of acceptor  atoms  is ∼ 10²¹ atoms/m³. Given that the intrinsic concentration of electron-hole pairs is 10¹⁹/m³,  the concentration of the specimen is

• 10¹⁷/m³

• 10¹⁵/m³

• 10⁴/m³

• 10²/m³