In a common emitter transistor amplifier, `beta=60, R_(0)=5000Omega` and internal resistance of a transistor is `500Omega`. The voltage amplification of the amplifier will be

Options

A. 500
B. 460
C. 600
D. 560

Answer

To find the voltage amplification (Av) of a common emitter transistor amplifier, we can use the following relationship:

1. **Identify the given values:**
- Current gain (β) = 60
- Output resistance (Ro) = 5000 Ω
- Internal resistance of the transistor (Ri) = 500 Ω

2. **Understand the relationships:**
- The output voltage (Vout) can be expressed as:
\[ V_{out} = I_c \times R_o \]
- The input voltage (Vin) can be expressed as:
\[ V_{in} = I_b \times R_i \]

3. **Relate collector current (Ic) and base current (Ib):**
- From the definition of current gain (β):
\[ \beta = \frac{I_c}{I_b} \Rightarrow I_c = \beta \times I_b \]
- Substituting this into the output voltage equation gives:
\[ V_{out} = (\beta \times I_b) \times R_o \]

4. **Substitute for Vin:**
- Now substituting for Vin:
\[ V_{in} = I_b \times R_i \]

5. **Calculate voltage gain (Av):**
- The voltage gain (Av) is defined as:
\[ A_v = \frac{V_{out}}{V_{in}} \]
- Substituting the expressions for Vout and Vin:
\[ A_v = \frac{(\beta \times I_b) \times R_o}{I_b \times R_i} \]
- The \(I_b\) terms cancel out:
\[ A_v = \frac{\beta \times R_o}{R_i} \]

6. **Plug in the values:**
- Now substituting the known values:
\[ A_v = \frac{60 \times 5000}{500} \]

7. **Calculate:**
- Simplifying:
\[ A_v = \frac{300000}{500} = 600 \]

Thus, the voltage amplification of the amplifier is **600**.