memo\" 14 A bar magnet is suspended above a coil of wire by means of a spring, as shown below: Time left 1:56:47 hot yet a nswere d Marked out of 1 .00 Spring W." Flag question Magnet Coil\\ The BOTTOM of the magnet is the SOUTH pole. The ends of the coil are connected to a sensitive galvanometer. The bar magnet is pulled down so that its north pole is level with the top of the coil. The magnet is released and the variation ofthe velocity vofthe magnet with the time t is shown below. Position 1 Position 2 On the diagram above. the point in the motion where the reading on the galvanometer is a maximum is position i i, and the point in the motion where the reading on the galvanometer is zero is position I QueS'iO" 1-5 Explainr in terms of magnetic field linesr why the reading on the galvanometer in the previous question is \"rm alte nating. {4 marks] answered Marked outof _ . _ _ 4m E Paragraph V B i 55 E El '9' a\" H l" Flag question Question 1 6 hot yet answered Below is a schematic diagram of a DC motor. The direction of the electron flow is OPPOSITE to the direction shown. The arrows Show the direction of POSITIVE current {an older. now obsolete concept}. The motor is rotating clockwise. Marked out of 2.00 '1" Flag question magnet coil Commutator {split ring) I I I brushes The direction of the electromagnetic force on the left side of the coil isI Ir and the direction of the electromagnetic force on the right side of the coil is = I. The poles on the magnet are not shown. The left part of the magnet is itsI : Ipole. and the right part ofthe magnet is its 3- pole. QueS'iO" 17 What is the purpose ofthe commutator in the DC motor from the previous question? Explain how it achieves its hotyet purpose. [2 marks) answered Marked out of ,_ ,_ 400 E Paragraph v B I! o .W III EQJE'E . '1.\" Flag