Solve problems involving electromagnetic induction using 𝑒𝑚𝑓 = − 𝑁∆(𝐵𝐴⊥) ∆𝑡, 𝑒𝑚𝑓 = −𝑁 ∆𝜙 ∆𝑡, 𝐼𝑝𝑉𝑝 = 𝐼𝑠 𝑉𝑠 and 𝑉𝑝 𝑉𝑠 = 𝑁𝑝 𝑁𝑠.

Refer to the graph below. a) Justify whether the induced emf in the coil is increasing, decreasing or remaining constant during the interval from 0.2 s to 0.5 s. b) Predict the effect on the peak induced emf if the number of turns in the coil were doubled while all other factors remained unchanged.

A square coil of 50 turns and side length 8.0 cm is placed perpendicular to a uniform magnetic field. The field strength decreases uniformly from 0.60 T to 0.20 T over 0.25 s. Identify the magnitude of the induced emf in the coil and state the physical principle that allows this emf to be generated.

A transformer is used to step down voltage from a power supply. The primary coil has 1,800 turns and is connected to a 240 V AC supply. The secondary coil has 150 turns and delivers a current of 4.5 A to a resistive load. (a) Calculate the voltage across the secondary coil. (1 mark) (b) Calculate the current in the primary coil. (1 mark) (c) Determine the power dissipated in the load resistor. (1 mark)

A solenoid with 30 loops of wire experiences a magnetic flux change of 0.45 Wb during a time interval of 0.18 s. Calculate the magnitude of the electromotive force (emf) induced in the solenoid.