$A$ square coil moves in a plane with uniform velocity $v$ parallel to its sides. $A$ magnetic field $B$ points perpendicular and into the loop. What is the induced current in the coil?

In domestic electrical wiring,what is the red-colored insulated wire used for?

$(a)$ Describe an activity to determine the direction of magnetic field produced by a current-carrying straight conductor. Also,show that the direction of the magnetic field is reversed on reversing the direction of current.
$(b)$ An $\alpha$-particle (which is a positively charged particle) enters a uniform magnetic field at right angles to it as shown below. Stating the relevant principle,explain in which direction will this $\alpha$-particle move?

Which instrument is used to know the presence of an electric current in a circuit?

What constitutes the field of a magnet?

$(a)$ What is the direction of magnetic field lines inside a bar magnet and outside of it?
$(b)$ What does the degree of closeness of the field lines represent?