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

On what factors does the resistance of a conductor depend?

Judge the equivalent resistance when the following are connected in parallel: $1 \, \Omega$,$10^3 \, \Omega$,and $10^6 \, \Omega$.

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	$12.9 \times 10^{-8}$

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

Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series and then parallel in a circuit across the same potential difference. The ratio of heat produced in series and parallel combinations would be -