Previous Year Questions

What will be the value of $\mathrm{R}$ in the following circuit? 

How many times will the total resistance of $\mathrm{n}$ identical resistors be reduced if the series arrangement is changed to a parallel one?

You are given three equal resistors. How many resistances can be obtained by joining them in series and parallel grouping?

A bulb of supply $(220 \mathrm{V}, 60 \mathrm{W})$ is operated on $110 \mathrm{V}$ the power dissipated in it is.

The reading of ideal voltmeter connected across $R$ in the circuit shown below is

A comb runs through one’s dry hair attracts small bits of paper. This is due to:

A wire of resistance $\mathrm{R}$ is stretched to twice of its original length. Its new resistance will be:

Consider two conducting plates A and B, between which the potential difference is $5 \mathrm{V}$, plate A being at a higher potential. A proton and an electron are released at plates A and B respectively. The two particles then move towards the opposite plates the proton to plate B and the electron to plate A. Which one will have a larger velocity when they reach their respective destination plates.