AC Circuit

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 -

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

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

The mass of the earth is 6 x 10²⁴ kg. The distance between the earth and the Sun is 1.5x 10¹¹ m. If the gravitational force between the two is 3.5 x 10²² N, what is the mass of the Sun?