Answer to Question 6

A solenoid has a diameter of 2.0 cm and a length of 5.0 cm. It has 150 turns and the core has a relative permeability of 120. Calculate the EMF induced when the rate of change of current is 60.0 A s^{1}. If the solenoid is connected to a 12.0 V power supply, calculate the voltage that would be measured by a datalogger. 
Work out the area first: A = p × (1.0 × 10^{2} m)^{2} = 3.14 × 10^{4} m^{2}
E = () (3.14 × 10^{4} m^{2} × 4p × 10^{7} H m^{1} × 120 × 150^{2} × 60.0 A s^{1}) ÷ 5.0 × 10^{2} m = () 1.28 V = () 1.3 V (2 s.f.)
V = 12.0  1.28 = 10.7 V 