What is meant by the term "magnetic field lines"? List two properties of magnetic field lines.

Differentiate between overloading and short-circuiting.

In our daily life,we use two types of electric current whose current-time graphs are given below:
$(i)$ Name the type of current in two cases.
$(ii)$ Identify any one source for each type of current.
$(iii)$ What is the frequency of current in case $(b)$ in our country?
$(iv)$ On the basis of these graphs,list two differences between the two currents.
$(v)$ Out of the two,which one is used in transmitting electric power over long distances and why?

The magnetic field produced by a current flowing through a straight conductor is inversely proportional to the $........$.

What is the pattern of field lines inside a solenoid? What do they indicate?

Which instrument works on the principle of 'Electromagnetic induction'?