Table of Contents
- 1 Why does the coil rotate when there is a current?
- 2 What factors would affect how fast the coil rotates?
- 3 Does the coil continue to rotate when the current is off?
- 4 What is the direction of the current induced in the coil?
- 5 How can the turning effect on the coil be increased?
- 6 What is motor effect of current electricity?
- 7 What happens when current increases in a coil?
- 8 How does a current carrying coil turn in a magnetic field?
- 9 Is the rotation of a circular coil normal to the field?
Why does the coil rotate when there is a current?
The coil of wire is mounted in the gap between the two magnets. The split rings make electrical contact with the coil and reverse the current every half turn. When an electric current flows through the coil, a force is exerted on the coil, causing it to spin.
What factors would affect how fast the coil rotates?
The speed of rotation of the coil can be increased by:
- increasing the size of the current;
- using a stronger magnet;
- increasing the number of turns of wire in the coil;
- reducing friction between the coil and the axel it rotates on.
Does the coil continue to rotate when the current is off?
When you give the coil a spin, since one side of the wire is insulated, you break the circuit briefly, so the coil continues to rotate using its momentum. When the circuit is complete again, the magnetic field once again repels the coil, so it keeps spinning. The motor can continue to spin until the battery is dead!
What causes motor to rotate?
A coil of wire carrying a current in a magnetic field experiences a force that tends to make it rotate. This effect can be used to make an electric motor.
What is the direction of the current induced in the coil if the current in the wire increases?
Since the resultant magnetic flux in the coil due to wire is into the plane of the coil, as current in the wire increases, the induced current in the coil will be to oppose the flux due to the wire. Hence the direction of the induced current in the coil will be counter clock wise.
What is the direction of the current induced in the coil?
Since current is increasing, the magnetic field also increases which results in induction of current in the coil. Applying Lenz law, the direction of induced current through the coil is anti-clockwise.
How can the turning effect on the coil be increased?
Summary points: split-ring commutators reverse the direction of the current in the coil each half turn. This allows the motor coil to rotate continuously in one direction. To increase the turning effect of the coil in the motor: Increase the number of turns in the coil.
What is motor effect of current electricity?
A current-carrying wire or coil can exert a force on a permanent magnet. This is called the motor effect. The wire could also exert a force on another nearby current-carrying wire or coil.
Why the coil continues to rotate in the same direction even though there is no current flowing in the coil?
The inertia of the rotating coil will make the paper clip touch the exposed copper wire on the other half curved surface again resulting in induced forces acting on the coil once more in same direction on each side of the coil after one complete turn. This ensures the coil continues to rotate in the same direction.
What causes the coil to continue spinning when current is not flowing?
The permanent magnet attracts its opposite pole on the coil and repels its like pole, causing the coil to spin. By painting half of one end black, you prevent current from flowing for half of each spin.
What happens when current increases in a coil?
I understand that when current is increased throughout a coil, the magnetic field (B) increases it’s strength. I try to compare this with a permanent magnet.
How does a current carrying coil turn in a magnetic field?
A current-carrying coil in a magnetic field experiences a turning effect. In Figure, a rectangular coil ABCD carries a current in the magnetic field between two magnadur magnets. (a) The sides BC and DA carry currents with directions parallel to the magnetic field.
Is the rotation of a circular coil normal to the field?
Consider a circular coil of ‘n’ turns of each area A placed with its plane perpendicular to a uniform magnetic field of induction B. At time t = 0, the plane of the coil is normal to field. Therefore, the magnetic flux passing through it is given by
What happens to the speed of rotation when the current increases?
Therefore, the speed of rotation increases when the current in the coil is increased. The strength of the magnetic field is increased by adding one more pair of magnadur magnets. By comparing the observations in steps 2 and 5, the speed of rotation increases when the strength of the magnetic field is increased.