An $n-p-n$ transistor having A.C. current gain of 50 is to be used to make an amplifier of voltage gain 6. What will be the power gain in the amplifier?

1. 300

2. 600

3. 750

4. 400

In a common emitter circuit, if V_CC is changed by 0.2 V, collector current changes by 4 x 10^–3 mA. The output resistance will be:

1. 10 k$\mathrm{\Omega }$ 

2. 30 k$\mathrm{\Omega }$ 

3. 50 k$\mathrm{\Omega }$ 

4. 70 k$\mathrm{\Omega }$

In a transistor circuit shown here, the base current is  35 $\mathrm{\mu }$A  and the potential difference across emitter-base junction is 4.5 V. The value of the resistor R_b is:
                 

1. 128.5 k$\mathrm{\Omega }$

2. 257 k$\mathrm{\Omega }$

3. 380.05 k$\mathrm{\Omega }$

4. None of these

The input resistance of a silicon transistor is 100 Ω. If the base current is changed by 40 µA, it results in a change in collector current by 2 mA. This transistor is used as a common emitter amplifier with a load resistance of 4 kΩ. The voltage gain of the amplifier is:

1.  3000 

2.  4000 

3.  1000 

4.  2000

In a common-emitter transistor amplifier, the audio signal voltage across the collector is 3 V. The resistance of the collector is 3 k$\Omega$. If the current gain is 100 and the base resistance is 2 k$\Omega$, the voltage and power gain of the amplifier are:

1. 200 and 1000

2. 15 and 200

3. 150 and 15000

4. 20 and 2000

A n-p-n transistor operates in a common emitter mode as shown. The value of \(R_{L}\) is:
\(\small\left ( \text{Given,}I_{C}=4 mA,~V_{CE}=4~V,V_{BE}=0.6~V~\text{and}~\beta _{dc}=100 \right )\\\)
        

1. 1 k$\Omega$

2. 2 k$\Omega$

3. 3 k$\Omega$

4. 4 k$\Omega$

If a common emitter circuit is used as an amplifier, its current gain is \(50.\) If input resistance is \(1\) kΩ and input voltage is \(5\) V, then output current will be:
1. \(250\) mA
2. \(30\) mA
3. \(50\) mA
4. \(100\) mA

Transfer characteristic [output voltage $\left(V_{\mathrm{o}}\right)$ vs input voltage $\left(V_i\right)$] for a base biased transistor in CE configuration is as shown in the figure. For using transistor as a switch, it is used:
                     

1. in region III

2. both in region (I) and (III)

3. in region II

4. in region I

In a common emitter amplifier, the phase difference between input signal and output signal is:

1. zero             

2. $\mathrm{\pi }$               

3. $\frac{\mathrm{\pi }}{2}$               

4. $\frac{\mathrm{\pi }}{4}$

In the circuit given below, if $V_{CE}$ is 5 V and $R=4\times {10}^5\Omega$, then current gain is:
(Neglect \(V_{BE}\))
           

1. 97

2. 98

3. 99

4. 100