K A Tsokos Solutions for Chapter: Electromagnetic Induction (HL), Exercise 1: Test yourself

A metallic ring is dropped from a height above a bar magnet as shown in the diagram. Find the direction of magnetic force on the metallic ring as it enters into its magnetic field.

A metallic ring is dropped from a height above a bar magnet as shown in the diagram. Find the direction of the magnetic force on the metallic ring as it leaves its magnetic field.

A metallic rod of length $L$ is dragged with constant velocity $v$ in a region of magnetic field directed into the page (shaded region), as shown in the diagram. By considering the force on electrons inside the rod, show that the ends of the rod will become oppositely charged. Determine the end that is positively charged.

Find the direction of the induced current in the loop, shown in the diagram, as the current in the straight wire increases.

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Find the direction of the current in the loop shown in the diagram as the current in the straight wire decreases.

A large coil has a smaller coil inserted inside it so that their axes are parallel. The smaller coil has $200$turns and a diameter of $2.0 \mathrm{cm}$. A changing current in the large coil causes the magnetic field to be increasing at a rate of $0.45 \mathrm{T} {\mathrm{s}}^{-1}$. Calculate the emf induced in the smaller coil.

Look at the diagram. The rod AB is free to move. The magnetic field is increasing. Determine what will happen to the rod AB.

Two identical rings made out of conducting material are released from rest, from the same height above the ground. One ring will fall through a region of a horizontal magnetic field. State and explain which ring will reach the ground first, given that they are released at the same time.