Find the resistance of a bulb rated as $100 \, W - 250 \, V$.

What is potential difference? Is it a scalar quantity or a vector quantity? Give its $SI$ units.

What is the main principle involved in a Voltaic cell?

$A$ potential difference $V$ is applied across a conductor of length $L$ and diameter $D$. How is the resistance $R$ of the conductor affected,when in turn $(i)$ $V$ is halved,$(ii)$ $L$ is halved,and $(iii)$ $D$ is doubled? Justify your answer in each case.

In the following circuits (Figure),heat produced in the resistor or combination of resistors connected to a $12\, V$ battery will be

Two wires of the same metal have the same length, but cross-sections are in the ratio $3 : 1$. They are joined in series. The resistance of the thicker wire is $10\, \Omega$. The total resistance of the combination will be: