When a transistor is used in a common emitter mode as an amplifier:
1. | the base-emitter junction is forward biased. |
2. | the base-emitter junction is reverse biased. |
3. | the base-collector junction is forward biased. |
4. | the input is connected in series with voltage applied across the base-collector junction. |
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) & (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
The output in the circuit shown in the figure taken across a capacitor is:
1. | 2. | ||
3. | 4. |
1. | the drift of holes. |
2. | diffusion of charge carriers. |
3. | migration of impurity ions. |
4. | drift of electrons. |
1. | (i) < (ii) < (iii) | 2. | (iii) < (ii) < (i) |
3. | (ii) = (iii) < (i) | 4. | (i) = (iii) < (ii) |
The combination of gates shown below is equivalent to:
1. AND gate
2. XOR gate
3. NOR gate
4. NAND gate
Find the base resistance in the circuit below, if \(\beta_{DC} =90\) and \(V_{BE}=0.7~V.\)
1. 83
2. 41 k
3. 83 k
4. 41
In an NPN transistor, 108 electrons enter the emitter in s. If 1% electrons are lost in the base, the fraction of current that enters the collector and the current amplification factor are, respectively:
1. 0.7 and 50
2. 0.9 and 90
3. 0.8 and 49
4. 0.99 and 99