What is the resistance of an electric arc lamp,if the lamp uses $20\, A$ when connected to a $220\, V$ line?

Define power. State the difference between $1$ watt and $1$ watt hour. Establish the relationship between the commercial unit of electric energy and the $SI$ unit of energy. An electric heater rated $1000 \ W / 220 \ V$ operates for $2$ hours daily. Calculate the cost of energy to operate it for $30$ days at the rate of ₹ $5.00$ per $kWh$.

The resistance of a piece of rubber is higher than that of a piece of copper of the same dimensions.

$(a)$ In the circuit shown, connect a nichrome wire of length $L$ between points $X$ and $Y$ and note the ammeter reading.
$(i)$ When this experiment is repeated by inserting another nichrome wire of the same thickness but twice the length $(2L)$, what changes are observed in the ammeter reading?
$(ii)$ State the changes that are observed in the ammeter reading if we double the area of cross-section without changing the length in the above experiment. Justify your answer in both cases.
$(b)$ "Potential difference between points $A$ and $B$ in an electric field is $1\, V$." Explain the statement.

When three resistors of $5 \Omega$,$10 \Omega$,and $30 \Omega$ are connected in parallel in a circuit,what will be the equivalent resistance?

An electric kettle consumes $1\, kW$ of electric power when operated at $220\, V$. $A$ fuse wire of what rating (in $A$) must be used for it?