Question

A resistance-capacitance relaxation circuit is used in an electrical discharge machining process. The discharge voltage is 100 V. At a spark cycle time of 25 $\mu$s, the average power input required is 1 kW. The capacitance (in $\mu$)F in the circuit is

• A. 2.5
• B. 5.0
• C. 7.5
• D. 10.0

Answer 1

The correct option is B 5.0

$Power=\frac{Work}{Time}$

$P=\frac{1}{2}\frac{C{V}^2}{t}$

$C=\frac{P\times 2t}{V^2}=\frac{1000\times 2\times 25\times {10}^{-6}}{{\left(100\right)}^2}$

$=5\mu F$