Physics 30: Assignment 7 ASSIGNMENT 7 48 Part One: Moving Charges in Magnetic Fields Marks The value of each question is noted in parentheses in the left margin. Note: The answer Total areas will expand to fit the length of your response. 1 . State the direction of the magnetic force on the moving charge in each diagram below. You may wish to verify your answers using the online simulation. (1) a. positive charge O O O O O O Answer: ( 1 ) b. positive charge X X X X X X X (X Answer: (1) c. negative charge X X X X X X X (X Answer: (1) d. negative chargePhysics 30: Assignment 7 2 O O O O O Answer: (4) 2. An electron experiences a downward magnetic force of 7.20 x 10-14 N when it is travelling at 3.00 x 105 m/s south through a magnetic field. Calculate the magnitude of the magnetic field and determine its direction using the left-hand rule. Explain all finger directions and the palm direction. Answer: (2) 3. A charged particle is travelling west through a downward magnetic field and it experiences a magnetic force directed to the north. Using the appropriate hand rule, determine if the charge is negative or positive. Explain all finger directions and the palm direction. Answer: (4) 4. Calculate the magnitude and the direction of the magnetic force acting on an alpha particle that is travelling upwards at a speed of 3.00 x 105 m/s through a 0.525 T west magnetic field. Explain all finger directions and the palm direction. Answer: (3) 5. An electron (m = 9.11 x 10-31 kg) enters a downward magnetic field of 5.00 x 10-1 T with a velocity of 6.50 x 105 m/s West. Calculate the radius of the circular path it will follow once it is travelling within the magnetic field. Answer: STOP! When you have completed all of the questions in Part One, save your work to your desktop. You will return to this assignment to complete Part Two after you have completed the remainder of the content in the next section.Physics 30: Assignment 7 Part Two: Electromagnetic Induction The value of each question is noted in the left margin in parenthesis. Note: The answer areas will expand to fit the length of your response. 1. A compact fluorescent light bulb draws a current of 0.10 A for one hour. (2) a. How much charge flows through the bulb in one hour? Answer: (2) b. How many electrons flow through the light bulb in the hour? Remember the charge of one electron is the elementary charge on your physics data sheet. Answer: (2) 2. A motor uses a coil of wire in a magnetic field to generate force. The motor draws a current of 9.50 A through the coil of wire and has a magnetic field of 1.75 T. If the motor is designed to generate 800 N, how long is the wire in the coil assuming that all of the wire creates force? Answer: (2) 3. Provide a brief description of how an electric motor uses the interaction between permanent and electromagnets to turn. Answer:Physics 30: Assignment 7 In the diagrams below, a magnet is either dropped down or pulled up through a solenoid (a cylinder encircled by a current-carrying conductor). Depending on what is asked for in questions a through e, (the "?"), indicate whether the magnetic pole is north or south and/or whether the motion of the magnet is up or down. (1 ) a. Determine the induced magnetic poles of the solenoid. N S G Answer: (1 ) b. Determine the induced magnetic poles of the solenoid. N S Answer:Physics 30: Assignment 7 5 (1) c. Determine if the permanent magnet is pulled up through the solenoid or pushed down through the solenoid. S N Answer: (2) d. Explain your use of a hand rule to determine the magnetic poles of the permanent magnet and the induced poles of the solenoid in the diagram below. ? S Answer:Physics 30: Assignment 7 (2) e. Explain your use of a hand rule to determine if the magnet is pulled up through the solenoid or pushed down through the solenoid and determine the induced magnetic poles of the solenoid. (2 marks) N S Answer: 5. Using the formulas for magnetic force, describe how each of the following factors influences the magnitude of the magnetic force and give the reason. (2) a. Strength of the magnetic field Answer: (2) b. Speed of the magnet passing through the coil Answer: (2) c. The number of loops wrapped around a cylinder Answer: (2) d. The current Answer:Physics 30: Assignment 7 (2) 6. Explain why the generator effect would occur in the same way if the wire was moved rather than the magnet. Answer: (2) 7. Would two parallel wires carrying a current in opposite directions repel or attract one another? Explain your answer. B X Answer: (4) 8. A 0. 120 m long copper wire has a mass of 9.02 g and is carrying a current of 5.10 A perpendicular to a uniform magnetic field. The apparatus is placed in a strong magnetic field and the wire is found to levitate. Calculate the magnetic field strength. Remember to show all work. Answer: When you have completed all of the questions in this assignment, submit your work to the Assignment 7 Dropbox