A light bulb is rated 100W for 220 V AC supply of 50 Hz. Calculate (a) resistance of the bulb. (b) the rms current through the bulb.

the given can be listed as

Power P = 100W

$V_{rms}=220 V$

To Find , Resistance R = ?

$I_{rms}=?$

Solution -

$R=\frac{V_{rms}^{2}}{P}=\frac{220\mathrm{x}220}{100}=484\Omega$

$I_{rms}=\frac{P}{V_{rms}}=\frac{100}{220}=\frac{1}{2.2}=0.45A$

In a hydraulic lift, the input piston had surface area 30 cm² and the output piston has surface area of 1500 cm² . If a force of 25 N is applied to the input piston, calculate weight on output piston.