Which of the following materials has more number of free electrons?
Copper
Glass
Rubber
Paper
What will happen to the current flowing through a conductor, if the potential difference is doubled ?
Which effect of electric current is used in electroplating?
Two resistors of resistance $2 \,\Omega $ and $4\, \Omega $ when connected to a battery will have
$A$ hot plate of an electric oven, connected to a $200 \,V$ line. It has two resistance coils $A$ and $B$ each of the $30\, \Omega$ which may be used separately, in series or in parallel. Find the value of the current required in each of the three cases.
Give a single word for $\frac{1 \text { joule }}{1 \text { coulomb }}$.