$A$ beam of alpha particles enters a chamber moving along a magnetic field. What is the magnetic force experienced by the beam?

Explain what is short-circuiting and overloading in an electric supply.

The horizontal component of the Earth's magnetic field at a place is uniform and its direction is from south to north. $A$ high current flows through a horizontal power line at this place from west to east. Consider two points $A$ and $B$ at equal distances from the wire,respectively above and below it. Giving reasons,explain where the magnetic field is stronger: at $A$ or at $B$.

$AB$ is a current-carrying conductor in the plane of the paper as shown in the figure. What are the directions of the magnetic fields produced by it at points $P$ and $Q$? Given $r_1 > r_2$, where will the strength of the magnetic field be larger?

State one main difference between $AC$ and $DC$. Why is $AC$ preferred over $DC$ for long-range transmission of electric power? Name one source each of $DC$ and $AC$.

$(a)$ What is an electromagnet? What does it consist of?
$(b)$ Name one material in each case which is used to make a: $(i)$ permanent magnet $(ii)$ temporary magnet.
$(c)$ Describe an activity to show how you can make an electromagnet in your school laboratory.