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. \(654\times 10^{-11}~\text{m}\)
1. | \(1.0 \times 10^6 ~\text{V/m}\) | 2. | \(1.0 \times 10^5 ~\text{V/m}\) |
3. | \(2.0 \times 10^5 ~\text{V/m}\) | 4. | \(2.0 \times 10^6 ~\text{V/m}\) |
1. | \(5\) A | 2. | \(0.2\) A |
3. | \(0.6\) A | 4. | zero |
Which logic gate is represented by the following combination of logic gates?
1. OR
2. NAND
3. AND
4. NOR
1. | the potential is the same everywhere. |
2. | the \(\mathrm{p}\text-\)type is at higher potential than the \(\mathrm{n}\text-\)type side. |
3. | there is an electric field at the junction directed from the \(\mathrm{n}\text-\)type side to the \(\mathrm{p}\text-\)type side. |
4. | there is an electric field at the junction directed from the \(\mathrm{p}\text-\)type side to the \(\mathrm{n}\text-\)type side. |
1. | \(V_B\) increases, \(x\) decreases | 2. | \(V_B\) decreases, \(x\) increases |
3. | \(V_B\) increases, \(x\) increases | 4. | \(V_B\) decreases, \(x\) decreases |
Which of the energy band diagrams shown in the figure corresponds to that of a semiconductor?
1. | 2. | ||
3. | 4. |
The energy band diagrams for semiconductor samples of silicon are as shown. We can assert that:
1. | Sample \(X\) is undoped while samples \(Y\) and \(Z\) have been doped with a third group and a fifth group impurity respectively. |
2. | Sample \(X\) is undoped while both samples \(Y\) and \(Z\) have been doped with a fifth group impurity. |
3. | Sample \(X\) has been doped with equal amounts of third and fifth group impurities while samples \(Y\) and \(Z\) are undoped. |
4. | Sample \(X\) is undoped while samples \(Y\) and \(Z\) have been doped with a fifth group and a third group impurity respectively. |
If the reverse bias in a junction diode is changed from \(5\) V to \(15\) V then the value of current changes from \(38~\mu \text{A}\) to \(88~\mu \text{A}\). The resistance of junction diode will be:
1. \(4\times10^{5}\)
2. \(3\times10^{5}\)
3. \(2\times10^{5}\)
4. \(10^{6}\)
1. | 2. | ||
3. | 4. |