James Clerk Maxwell, a Scottish physicist, is considered the greatest theoretical physicist of the nineteenth century - Leaving Cert Physics - Question 9 - 2018

A pair of complementary colours of light is red and cyan.

A magnetic field is a region where magnetic forces are felt. It is produced by moving electric charges, such as those in a current-carrying wire.

To illustrate the magnetic field around a long straight current-carrying wire, draw a straight line representing the wire with concentric circles around it. Place arrows on the circles to indicate the direction of the magnetic field, which follows the right-hand rule.

For the solenoid, draw a rectangle to represent the solenoid coils, indicating the direction of current flow. Draw field lines entering and exiting the solenoid, demonstrating that inside the solenoid the magnetic field lines are parallel and close together, while outside, they spread out.

Faraday's law states that the emf induced in a circuit is proportional to the rate of change of magnetic flux through the circuit: ext{emf} = -rac{d heta}{dt}

An experiment to demonstrate Faraday's law could involve:

1. Using a coil, a galvanometer, and a magnet in a correct arrangement.
2. Move the magnet relative to the coil and observe the current on the galvanometer, showing that a changing magnetic field induces an emf.

To find the average emf induced in the coil, use Faraday's law:

1. The area of one side of the square coil is given by: $A = l^2 = (0.2 ext{ m})^2 = 0.04 ext{ m}^2$.
2. The total magnetic flux (Φ) is calculated as: $ext{Φ} = B imes A = (50 imes 10^{-3} ext{ T}) imes (0.04 ext{ m}^2) = 2 imes 10^{-3} ext{ Wb}$.
3. The average emf when rotated through 90° in 1 x of a second is: E = rac{ ext{ΔΦ}}{ ext{Δt}} = rac{2 imes 10^{-3} ext{ Wb}}{0.5 ext{ s}} = 0.32 ext{ V}.

Light is detected in the retina of the eye.

Two invisible parts of the electromagnetic spectrum that have shorter wavelengths than visible light are ultraviolet and X-rays.