An electric heater rated $1200 \ W$ operates $2 \ h$ per day. Find the cost of the energy required to operate it for $30$ days at ₹ $5.00$ per unit.

What is Joule's heating effect? How can it be demonstrated experimentally? List its four applications in daily life.

Which of the following substances does not contain free electrons?

$A$ bulb is rated $220\;V$ and $100\;W$. What is the resistance of this bulb?

$(i)$ Name and state the law that gives the relationship between the current through a conductor and the potential difference across its two terminals. Also,express this law mathematically.
$(ii)$ Draw the $V-I$ graph for this law. Justify your answer.
$(iii)$ Write the name and use of the circuit components whose symbols are given below:
$(a)$ $A$ resistor with an arrow through it.
$(b)$ $A$ circle with a dot inside,connected to two lines.

$1 \; kWh = \ldots \ldots \; \text{joules}$