The increase in the width of the depletion region in a \(\mathrm{p\text{-}n}\) junction diode is due to:
1. reverse bias only
2. both forward bias and reverse bias
3. increase in forwarding current
4. forward bias only

The solids which have the negative temperature coefficient of resistance are:

For the logic circuit shown, the truth table is:

Out of the following which one is a forward-biased diode?

1.
2.
3.
4.

Which of the following gate is called the universal gate? 
1. \(\mathrm{OR}\) gate 
2. \(\mathrm{AND}\) gate 
3. \(\mathrm{NAND}\) gate 
4. \(\mathrm{NOT}\) gate 

An intrinsic semiconductor is converted into an \(\mathrm{n\text{-}}\)type extrinsic semiconductor by doping it with: 
1. phosphorous
2. aluminium
3. silver
4. germanium

The circuit diagram shown here corresponds to the logic gate:

     
1. \(\text{NOR}\)
2. \(\text{AND}\)
3. \(\text{OR}\)
4. \(\text{NAND}\)

An LED is constructed from a \(\mathrm{p\text{-}n}\) junction diode using \(\mathrm{GaAsP}.\) The energy gap is \(1.9~\text{eV}.\) The wavelength of the light emitted will be equal to:
1. \(10.4 \times 10^{-26}~ \text{m}\)
2. \(654~ \text{nm}\)
3. \(654~ \text{m}\)
4. \(654\times 10^{-11}~\text{m}\)

The electron concentration in an \(\mathrm{n\text-}\)type semiconductor is the same as the hole concentration in a \(\mathrm{p\text{-}}\)type semiconductor. An external field (electric) is applied across each of them. Compare the currents in them.