Electromagnetism is caused by the magnetic fields around wires carrying an electric current. The induced magnetic field of a wire can interact with other nearby magnets, producing a force.
Which of the following is a way of working out which way the force on a current carrying wire will act when in a magnetic field?
Fleming’s right-hand rule
Fleming’s left-hand rule
The generator rule
What sort of force is generated when the current and the magnetic field are parallel to each other?
No force is generated
Maximum force is generated
Half the maximum force is generated
In Fleming’s left-hand rule, which finger represents the current?
The second finger
Which equation is used to calculate the force on a wire carrying a current at right angles to a magnetic field?
Force on a conductor carrying a current = magnetic field strength × length
Force on a conductor carrying a current = magnetic field strength × current × length
Force on a conductor carrying a current = magnetic field strength ÷ current × length
When using Fleming’s left-hand rule, what does the forefinger represent?
When using Fleming's left-hand rule, what does the thumb represent?
A 0.1 m length of wire carries a current of 0.4 A in a 0.7 T magnetic field. What force acts on the wire?
In a dc motor, what is the function of the split ring commutator?
It reverses the current direction every half turn, to keep the motor spinning in the same direction all the time
It shields the magnetic field from acting outside the motor case
It strengthens the magnetic field to make the motor spin fast on a lower current
A 0.1 m length of wire carries a current of 0.02 A in a 5 T magnetic field. What force acts on the wire?
Considering a current carrying wire in a magnetic field, which of the following graphs is not a straight line passing through the origin?
Magnetic field strength against current
Force against current
Force against magnetic field strength