Question 1:
With the aid of a labelled diagram, explain the meaning of catapult field.
Answer:
A catapult field is a resultant magnetic field produced by the interaction between the magnetic field from a current-carrying conductor with the magnetic field from a permanent magnet.
With the aid of a labelled diagram, explain the meaning of catapult field.
Answer:
A catapult field is a resultant magnetic field produced by the interaction between the magnetic field from a current-carrying conductor with the magnetic field from a permanent magnet.
Question 2:
Figure 4.15 shows the arrangement of apparatus to study the effect of a force on a current-carrying conductor.
(a) What is the direction of the current in the copper wire XY when the switch of the direct current power supply is turned on?
(b) Explain the motion of the copper wire XY and state the direction of the motion.
Answer:
(a) X to Y
(b) The current in copper wire XY produces a magnetic field that superimposes with the magnetic field from the permanent magnet.
The two magnetic fields combine to produce a catapult magnetic field.
The catapult magnetic field exerts a force on wire XY and moves the wire.
The direction of motion of wire XY is to the right.
Figure 4.15 shows the arrangement of apparatus to study the effect of a force on a current-carrying conductor.
(a) What is the direction of the current in the copper wire XY when the switch of the direct current power supply is turned on?
(b) Explain the motion of the copper wire XY and state the direction of the motion.
Answer:
(a) X to Y
(b) The current in copper wire XY produces a magnetic field that superimposes with the magnetic field from the permanent magnet.
The two magnetic fields combine to produce a catapult magnetic field.
The catapult magnetic field exerts a force on wire XY and moves the wire.
The direction of motion of wire XY is to the right.
Question 3:
State three factors that affect the speed of rotation of a motor.
Answer:
Current in the coil, number of turns of the coil, strength of magnetic field
State three factors that affect the speed of rotation of a motor.
Answer:
Current in the coil, number of turns of the coil, strength of magnetic field
Question 4:
(a) Compare and contrast the structure of a brushed motor with a brushless motor.
(b) State two advantages of brushless motor compared to brushed motor.
Answer:
(a) Both consist of a coil and permanent magnets
Brushed motor: The permanent magnet is stationary while the coil rotates
Brushless motor: The coil is stationary while the magnet rotates
(b) Lower level of operational sound
Lower maintenance cost
(a) Compare and contrast the structure of a brushed motor with a brushless motor.
(b) State two advantages of brushless motor compared to brushed motor.
Answer:
(a) Both consist of a coil and permanent magnets
Brushed motor: The permanent magnet is stationary while the coil rotates
Brushless motor: The coil is stationary while the magnet rotates
(b) Lower level of operational sound
Lower maintenance cost