Exercise

$90 \mathrm{J}$ of work is done in flowing $6 \mathrm{C}$ of positive charge between two points in an electric field. Find the potential difference between the two points.

What is the device that can maintain a potential difference across a conductor?

The potential at a point is $20 \mathrm{V}$. Calculate the amount of work done to bring a charge of $0.5 \mathrm{C}$ from infinity to this point?

What $p.d$ would cause a current of $3.0 \mathrm{A}$ to flow through a $10 \mathrm{\Omega }$ resistor?

What is the SI unit of potential difference? Define it.

What is a superconductor? Give an example of it.

Draw a symbol for the voltmeter.

Consider the given circuit and find the current flowing in the circuit and potential difference across the $15 \mathrm{\Omega }$ resistor when the circuit is closed.