A full wave precision diode rectifier uses a load resistance of 1200 Ω. The external resistance of each diode is 9 Ω. Find efficiency.

Steps to Solve

1. Identify Given Values We have the following values:

• Load resistance, $R_L = 1200 , \Omega$
• Internal resistance of each diode, $R_d = 9 , \Omega$
  Since it's a full wave rectifier, there are two diodes in operation.

2. Calculate Total Diode Resistance For a full-wave rectifier, the total resistance from both diodes is:
   $$ R_{total} = R_d + R_d = 9 , \Omega + 9 , \Omega = 18 , \Omega $$

3. Compute Total Resistance in the Circuit The total resistance in the circuit will be the sum of the load resistance and the total diode resistance:
   $$ R_{total_circuit} = R_L + R_{total} = 1200 , \Omega + 18 , \Omega = 1218 , \Omega $$

4. Calculate Efficiency The efficiency ($\eta$) of a rectifier can be calculated using the formula:
   $$ \eta = \frac{R_L}{R_{total_circuit}} = \frac{R_L}{R_L + R_d + R_d} $$
   Substituting the values:
   $$ \eta = \frac{1200}{1218} $$

5. Calculate the Efficiency Value Now compute the numerical value of the efficiency:
   $$ \eta \approx 0.983 , \text{or} , 98.3% $$