Draw a simple circuit of a CE transistor amplifier. Explain its working. Show that the voltage gain, `A_(v)`, of the amplifier is given by `A_(v)= -(beta_(ac) R_(I))/(r_(i))`, where `beta_(ac)` is the current gain, `R_(L)` is the load resistance and `r_(i )` is the input resistance of the transistor. What is the significance of the negative sign in the expression of the voltage gain ?

Explanation

### Step-by-Step Solution:

1. **Circuit Diagram**:
- Draw the circuit of a Common Emitter (CE) transistor amplifier.
- Include the transistor (NPN), input voltage source (V1), output load resistor (R_L), biasing resistors, and the power supply (V_CC).

2. **Working Principle**:
- In a CE amplifier, the input signal (V1) is applied between the base and emitter of the transistor. The output is taken from the collector to the emitter.
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