When a $CuSO_4$ cell and an $AgNO_3$ cell are connected in series and a current is passed through them,if $1 \, mg$ of copper is deposited in the first cell,how much silver (in $mg$) will be deposited in the second cell? $(A_{Cu} = 63.57, A_{Ag} = 107.88)$

An electric kettle has two coils. When one coil is switched on,the tea gets heated in $10 \, \text{min}$. When the other coil is switched on,the same amount of tea gets heated in $40 \, \text{min}$. If both coils are connected in parallel,how long will it take to heat the same amount of tea (in $, \text{min}$)?

For the circuits shown in figures $I$ and $II$,the voltmeter reading would be

Two cables of copper are of equal lengths. One of them has a single wire of area of cross-section $A$, while the other has $10$ wires of cross-sectional area $A / 10$ each. Determine their suitability for transporting $A.C.$ and $D.C.$

Two current elements $P$ and $Q$ have current-voltage characteristics as shown below. Which of the graphs given below best represents the current-voltage characteristics when $P$ and $Q$ are in series?

$A$ wire of length $L$ and $3$ identical cells of negligible internal resistances are connected in series. Due to current,the temperature of the wire is raised by $\Delta T$ in a time $t$. $A$ number $N$ of similar cells is now connected in series with a wire of the same material and cross-section but of length $2L$. The temperature of the wire is raised by the same amount $\Delta T$ in the same time $t$. The value of $N$ is