The correct symbol for zener diode is:
1. | 2. | ||
3. | 4. |
1. | 2. | ||
3. | 4. |
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. \(654\times 10^{-11}~\text{m}\)
Zener breakdown will occur if:
1. impurity level is low.
2. impurity level is high.
3. impurity is less on the \(\mathrm{n\text-}\)side.
4. impurity is less on the \(\mathrm{p\text-}\)side.
1. \(36~\text{mW}\)
2. \(12~\text{mW}\)
3. \(144~\text{mW}\)
4. \(72~\text{mW}\)
The LED:
1. is reverse-biased.
2. is forward-biased.
3. can be made of \(\mathrm{GaAs}\).
4. both (2) & (3) are correct.
A Zener diode is used to obtain a constant voltage. If applied voltage \(\text V\) changes, then:
(\(\text V\) is more than Zener voltage)
1. | \(i_{1}\) and \(i_{2}\) change. |
2. | \(i_{2}\) and \(\text V_{0}\) change and \(i_{3}\) remains constant. |
3. | \(i_{2}\) and \(\text V_{0}\) don't change while \(i_{3}\) changes. |
4. | \(i_{3}\) and \(\text V_{0}\) don't change while \(i_{2}\) changes. |
The given graph represents the \(V\text-I\) characteristic for a semiconductor device. Which of the following statement is correct?
1. | It is a \(V\text-I\) 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. |
A Zener diode is shown in the following circuit diagram. When the source voltage fluctuates such that \(V>V_z\) then:
1. | \(I_1, I_2~\text{and}~I_3\) change. | all the current
2. | \(I_1\) and \(I_2\) change and \(I_3\) remains constant. | only
3. | \(I_1\) and \(I_3\) change and \(I_2\) remains constant. | only
4. | all the currents remain constant. |