Waec Physics 2003 Past Questions and Answers

Question 61:

• WAEC 2003

(a)(i) What is meant by neutral point in a magnetic field?
(ii) Draw and label a diagram to show the pattern and direction of the magnetic field produced around a straight current-carrying wire.
(b) When is an ammeter said to be (i) Sensitive (ii) accurate?
(c)(i) Explain, using a labelled diagram, how a delicate magnetic material could be protected, from the Earth's magnetic field.
(ii) A charge of 1.6 x 10\(^{-19}\) C enters a magnetic field of flux density 2.0 T with a velocity of 2.5 x 10\(^7\) ms\(^{-1}\) at an angle of 30° with the field. Calculate the magnitude of the force exerted on the charge by the field.
(d) State the laws of electro-magnetic induction.