Carbon, Silicon, and Germanium atoms have four valence electrons each. Their valence and conduction bands are separated by energy gaps represented by \(\left(E_g\right)_C,(E_g)_{Si}~\text{and}~(E_g)_{Ge}\) respectively. Which one of the following relationships is true in their case?
1. | \(\left(E_g\right)_C<\left(E_g\right)_{G e} \) | 2. | \(\left(E_g\right)_C>\left(E_g\right)_{S i} \) |
3. | \(\left(E_g\right)_C=\left(E_g\right)_{S i} \) | 4. | \(\left(E_g\right)_C<\left(E_g\right)_{S i}\) |
A semiconductor is known to have an electron concentration of cm-3 and a hole concentration of cm-3. The semiconductor is:
1. n-type
2. p-type
3. intrinsic
4. insulator
If in a p-n junction, a square input signal of 10 V is applied as shown, then the output across RL will be:
1. | 2. | ||
3. | 4. |
The given graph represents the V-I characteristic for a semiconductor device. Which of the following statement is correct?
1. | It is a V-I characteristic for a solar cell where point A represents open-circuit voltage and point B represents short-circuit current. |
2. | It is for a solar cell and points A and B represent open-circuit voltage and current respectively. |
3. | It is for a photodiode and points A and B represent open-circuit voltage and current respectively. |
4. | It is for a LED and points A and B represent open-circuit voltage and short circuit current respectively. |
Pure Si at 500 K has equal number of electron and hole concentration of Doping by indium increases to The doped semiconductor is of:
1. | n-type with electron concentration \(n_{e}=5\times10^{22}~m^{-3}\) |
2. | \(n_{e}=2.5\times10^{23}~m^{-3}\) | p-type with electron concentration
3. | \(n_{e}=2.5\times10^{10}~m^{-3}\) | n-type with electron concentration
4. | \(n_{e}=5\times10^{9}~m^{-3}\) | p-type with electron concentration
The electrical circuit used to get smooth output from a rectifier circuit is called:
1. oscillator.
2. filter.
3. amplifier.
4. logic gates.
The correct symbol for zener diode is:
1. | 2. | ||
3. | 4. |
\({C}\) and \({Si}\) both have the same lattice structure, having \(4\) bonding electrons in each. However, \(C\) is an insulator whereas \(Si\) is an intrinsic semiconductor. This is because:
1. | in the case of \(C\), the valence band is not completely filled at absolute zero temperature. |
2. | in the case of \(C\), the conduction band is partly filled even at absolute zero temperature. |
3. | the four bonding electrons in the case of \(C\) lie in the second orbit, whereas in the case of \(Si\), they lie in the third. |
4. | the four bonding electrons in the case of \(C\) lie in the third orbit, whereas for \(Si\), they lie in the fourth orbit. |
The figure shows a logic circuit with two inputs \(A\) and \(B\) and the output \(C\). The voltage waveforms across \(A\), \(B\), and \(C\) are as given. The logic circuit gate is:
1. \(\mathrm{OR}\) gate
2. \(\mathrm{NOR}\) gate
3. \(\mathrm{AND}\) gate
4. \(\mathrm{NAND}\) gate