Physics 1989 Waec Past Questions and Answers

Question 36 :

• WAEC 1989

(a) State the laws of electromagnetic induction.
(b) (i) Describe a simple experiment to show how an induced e.m.f, can be produced; (ii) State two factors on which the magnitude of the induced e.m.f. depends
(c) Explain what is meant by the r.m.s. value of an alternating current
(d) (i) If the alternating current is represented by \(I = l_{o} \sin \omega t\), state what the symbol \(I, I_{o}, \omega\) and \(\omega t\)represent.
(ii) Calculate the instantaneous value of such a current, if in a circuit it has r.m.s value of 15.0A when its phase angle is 30°.