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A coil of wire containing N turns is in an external magnetic field that is perpendicular to the plane of the coil. The magnetic field is changing at a constant rate. An emf of V is induced in the coil as a result. If the rate of change of the magnetic field and the number of turns in the coil are now cut in half, what will be the induced emf in the coil? O V/4 O V/2 O 2V O 4V Question 10 1 pts A flat coil having 3000 turns, each with an area of 0.45 m, is placed with the plane of its area perpendicular to a magnetic field of 2 T. The magnetic field changes uniformly from 2 T in the ty- direction to 2 T in the -y-direction in 7 s. If the resistance of the coil is 4000 2, at approximately what rate is power generated in the coil during this change? O OW O 150 W O 75 W 115 WThe primary coil in a transformer has 3 A flowing through it at 140 V. What current can flow in the secondary coil at a voltage of 35 V? O 4 A O 12 A O 0.75 A O 7.5 A Question 2 1 pts At what rate must the area of a closed loop be changing if the magnitude of the induced emf in the loop is 3.5 V. Suppose the loop consists of 400 turns, and that it is immersed in a constant magnetic field of 2 T. 102 cm2/s O 77 cm2/s O 44 cm2/s O 26 cm2/s 0 A toroidal solenoid has a radius of 8 mm and a total of 400 turns of conductive wire wrapped around its circumference. If the current flowing through the wire is decreasing at a rate of 0.3 A/s, at what rate is the magnetic flux through the toroid changing? O 8.1 x 10 3 T-m2/s O 7.2 x 10 3 Tom2/s 3 x 10-3 T-m2/s O 1.3 x 10-3 T-m2/s -Question 4 1 pts A conducting rod of length 13 cm is placed on a U-shaped metal wire that is connected to a lightbulb having a resistance of 25 Q. A constant uniform magnetic field of strength 0.20 T is applied perpendicular to the plane of the U-shaped metal rails. An applied external force pulls the rod to the right with a constant speed of 3 m/s. What is the magnitude of the emf induced in the rod? O 0.92 V O 0.24 V O 1.1 V 0.08 VThe primary coil of a transformer has 200 turns and its secondary coil has 600 turns. If an AC voltage of 60 V is applied to the primary coil, what voltage is present in its secondary coil? O 40 V O 95 V O 180 V O 120 V Question 6 1 pt A bar magnet with its south pole points towards a closed circular loop. The bar magnet is moved towards the loop at a constant speed. As seen from the magnet's south pole, as it approaches the loop, in which direction is the induced current flowing in the loop? O counterclockwise O clockwise O the current rapidly oscillates O there is no current flowing You are observing two wire coils, coil A and coil B. Coil A is immersed in a constant magnetic field of 3T and coil B is immersed in a constant field of magnitude 7 T. Both coils have the same area and are oriented at right angles to the field. Which coil will have a greater emf induced in it? O The induced emfs in coil A and coil B are equal, O Coil B O Coil A O Cannot be determined Question 8 1 pts A flat square wire loop of side length 13 cm rotating in a uniform magnetic field of 1.7 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vector are at an angle of 60. O 2.62 T-m2 O 0.014 T-m2 O 0.229 T.m2 O 1.38 T-m2