Q. No.
Which of the following-junction is used unbiased?
1. Photo diode
2. LED
3. Zener diode
4. Solar cell
1. \(36~\text{mW}\)
2. \(12~\text{mW}\)
3. \(144~\text{mW}\)
4. \(72~\text{mW}\)
The \((I\text-V)\) characteristics of a \(\mathrm{p\text-n}\) junction diode is as shown. If \(R_1\) and \(R_2\) be the dynamic resistance of the \(\mathrm{p\text-n}\) junction when (i) a forward bias of \(1\) volt is applied and (ii) a forward bias of \(2\) volts is applied respectively, then \(\frac{R_1}{R_2}=?\)
1. \(160\)
2. \(16\)
3. \(1.6\)
4. \(0.16\)
Current \(I_1\) through the Zener diode shown in the circuit is:
1. Zero
2. \(0.6\) mA
3. \(0.2\) mA
4. \(0.8\) mA
| 1. | only if both inputs are zero. |
| 2. | if either or both inputs are \(1\). |
| 3. | only if both inputs are \(1\). |
| 4. | if any of the inputs is zero. |
(If diodes are ideal)
| 1. | \(0,0\) | 2. | \(5~\text{mA},5~\text{mA}\) |
| 3. | \(5~\text{mA},0\) | 4. | \(0,5~\text{mA}\) |
The LED:
| 1. | is reverse-biased. |
| 2. | is forward-biased. |
| 3. | can be made of \(\mathrm{GaAs}.\) |
| 4. | both (2) and (3) are correct. |
Logic gates \(X\) and \(Y\) have the truth tables shown below:
| \(X\) | ||
| \(P\) | \(Q\) | \(R\) |
| \(0\) | \(0\) | \(0\) |
| \(1\) | \(0\) | \(0\) |
| \(0\) | \(1\) | \(0\) |
| \(1\) | \(1\) | \(1\) |
| \(Y\) | |
| \(P\) | \(R\) |
| \(0\) | \(1\) |
| \(1\) | \(0\) |
When the output of \(X\) is connected to the input of \(Y\), the resulting combination is equivalent to a single:
1. NOT gate
2. OR gate
3. NAND gate
4. AND gate
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