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How do you figure out which way the motor will spin (figure 12)? And how do you figure out which way the loop will rotate?
And to answer 1. c), how do you even figure out which way the current is going if you don't have any information (which part of the coil is the north pole, which way was the original current direction...)?
Please check these answers:
3. a) increasing the number of loops in the coil would increase the magnetic field
b) a plastic core wouldn't produce a magnetic field
c) decreasing the current would decrease the magnetic field
I need help with these... I think my problem with answering these stems from the issues I stated above.
d) reversing the polarity of the external magnets would ...?
e) reversing the polarity of the external magnets and reversing the direction of the current would...?
To figure out the direction in which the motor will spin (figure 12) and the direction in which the loop will rotate, you can apply the right-hand rule.
For the motor to spin, you first need to determine the direction of the magnetic field within the motor. This is determined by the direction of the current flowing through the coil. If you don't have any information about the current direction or the polarity of the coil, you can assume arbitrary directions for the current flow (clockwise or counterclockwise) and the coil's polarity (north pole on top or bottom). These assumptions will help you determine the magnetic field direction.
Using the right-hand rule, you can curl your fingers in the direction of the magnetic field created by the coil. Your thumb will then point in the direction of the force on the coil wire. The coil will experience a force in the opposite direction of the force acting on the loop, causing it to rotate.
For determining the loop's rotation, you can again use the right-hand rule. Point your thumb in the direction of the force on the loop due to the magnetic field. Extend your fingers as if you were wrapping them around the loop in the direction of the current flow. Your fingertips will point in the direction of the loop's rotation.
Now, let's address the answers you have provided:
a) Increasing the number of loops in the coil would increase the magnetic field: This answer is correct. According to Faraday's law, the magnetic field strength increases with the number of turns in the coil.
b) A plastic core wouldn't produce a magnetic field: This answer is also correct. A plastic core doesn't have magnetic properties and, therefore, won't produce a magnetic field.
c) Decreasing the current would decrease the magnetic field: This answer is incorrect. According to Ampere's law, the magnetic field strength is directly proportional to the current flowing through the coil. Decreasing the current would reduce the magnetic field.
Now let's tackle the remaining questions:
d) Reversing the polarity of the external magnets would: Reversing the polarity of the external magnets would change the direction of the magnetic field. This change in the magnetic field's direction can affect the rotation or movement of the motor or loop, depending on the specific setup.
e) Reversing the polarity of the external magnets and reversing the direction of the current would: By reversing the polarity of the external magnets and reversing the direction of the current, you will effectively change the direction of both the electric current flowing through the coil and the magnetic field created by the external magnets. This change can also affect the rotation or movement of the motor or loop, based on the specific configuration.
Remember, these answers may vary depending on the specific setup and conditions given in the problem.