1a) Without a commutator, an electric motor would A) not move at all B) go too fast and burn out C) not allow current to flow through it D) go back and forth instead of always rotating in the samedirection E) stop after at most half a turn 1b.) twocurrent loopsare parallel to one another. theforce between them is attractive: A) never B) always C) when their currents are in the same direction (e.g., both areclockwise) D) when their currents are in opposite directions (e.g., one isclockwise, one is counter-clockwise) 1c) In the righthand rule for the B field at the center of a loop ofcurrent: A) The fingers curve in the direction of the B field, the thumbpoints in the direction of the current. B) The fingers curve in the direction of the current, the thumb isthe direction of the B field. C) The middle finger points towards the center of the loop, theindex finger points towards the B field, and the thumb point in thedirection of the current. D) The middle finger points towards the B field, the index fingerpoints towards the center of the loop, and the thumb point in thedirection of the current. 1d) You are adistance R from the center of a loop of current and from a straightline of current (both have the same current). What can you sayabout the magnitude of the two B fields? A) The B field from the line is about 2 times stronger than the Bfield from the loop B) The two B fields are the same magnitude C) The B field from the line is about 3 times stronger than the Bfield from the loop D) The B field from the loop is about 3 times stronger than the Bfield from the line E) The B field from the loop is about 2 times stronger than the Bfield from the line 1e) Anelectromagnet with an iron core amplifies the magnetic field due tothe magnet itself by: A) aligning the magnetic domains in the iron with the field of theelectromagnet B) scrambling the magnetic domains in the iron using theelectromagnet C) orienting the magnetic domains in the iron perpendicular to thefield of the electromagnet 1f) A solenoidhas a: A) Strong uniform B field inside, directed radially outwards fromthe solenoid, small B field outside B) Strong uniform B field outside, directed along the axis of thesolenoid, small B field inside C) Strong uniform B field inside, directed along the axis of thesolenoid, small B field outside D) Strong uniform B field outside, directed radially outwards fromthe solenoid, small B field inside 1g)A magneticdipole experiences no torque in a magnetic field: A) when the magnetic dipole moment is perpendicular to the Bfield B) when the B field is uniform C) when the magnetic dipole moment points in the direction of the Bfield