Question

A 50F capacitor in a medical instrument is charged to 300V. The energy stored in the capacitor is sent through the patients brain during a pulse of duration 2 milliseconds. What is the power delivered to the brain of the patient?

• A. 500 W
• B. 600 W
• C. 750 W
• D. 12500 W

Answer 1

The correct option is D 12500 W

$C=$ Capacitance of capacitor$=50\mu F=50\times {10}^{-6}F$

$V=$ Potential Difference to which capacitor is charged $=3000volt$

$E=$ Energy stored by the capacitance

$E=\left(0.5\right)C{V}^2$

Inserting the value given above

$E=\left(0.5\right)(50\times {10}^{-6})(3000{)}^2=(0.5\left)\right(50\times {10}^{-6}\left)\right(9\times {10}^6)=(0.5\left)\right(50\left)\right(9)=225J$

$t=$ Time duration of the pulse$=2ms=0.002s$

Power given as $P=\frac{E}{T}=\frac{225}{0.002}=12500watt$