Which uses more energy, a $250 \,W$ $TV$ set in $1 \,hr$ or a $1200 \,W$ toaster in $10$ minutes?

An electric bulb is rated $220\, V$ and $100\, W$. When it is operated on $110\, V$,the power consumed will be ....... $W$.

Calculate the number of electrons constituting one coulomb of charge.

Will current flow more easily through a thick wire or a thin wire of the same material,when connected to the same source? Why?

$A$ copper wire has a diameter of $0.5\, mm$ and a resistivity of $1.6 \times 10^{-8}\, \Omega \, m$. What will be the length of this wire to make its resistance $10\, \Omega$? How much does the resistance change if the diameter is doubled?

Use the data in the table to answer the following: Which material is the best conductor?

Material	Resistivity $(\Omega \,m)$
Silver	$1.6 \times 10^{-8}$
Copper	$1.62 \times 10^{-8}$
Aluminium	$2.63 \times 10^{-8}$
Tungsten	$5.20 \times 10^{-8}$
Nickel	$6.84 \times 10^{-8}$
Iron	$10.0 \times 10^{-8}$
Chromium	$12.9 \times 10^{-8}$