Electric Motor Performance and Magnetism

The video tutorial explores the factors affecting the force on a wire carrying an electric current in a magnetic field. It discusses the role of current, magnetic flux density, and wire length in determining the force. The tutorial introduces the formula F = BIL, explaining how each variable contributes to the force. It also highlights practical considerations in building electric motors, such as the impact of high currents and wire loops. The video concludes with a calculation example to reinforce the concepts.

Which of the following is NOT a factor affecting the performance of an electric motor?

• Current

• Wire length

• Magnet strength

• Color of the wire

What does the current flowing through a wire create around it?

• Thermal field

• Gravitational field

• Magnetic field

• Electric field

Magnetic flux density is measured in which unit?

• Joule

• Tesla

• Ampere

• Newton

What is the approximate magnetic flux density of a typical weak fridge magnet?

• 2 Tesla

• 0.001 Tesla

• 1.5 Tesla

• 0.1 Tesla

How does increasing the length of wire in a magnetic field affect the force experienced?

• Reverses the force direction

• Has no effect

• Increases the force

• Decreases the force

What is the formula that links magnetic flux density, current, and wire length to force?

• F = ILB

• F = LIB

• F = BLI

• F = BIL

What is a potential problem when using higher currents in electric motors?

• Decreased wire length

• Increased magnetic flux

• Decreased efficiency

• Increased heating

If a wire is looped around multiple times in a magnetic field, what happens to the force?

• It increases

• It decreases

• It reverses direction

• It remains the same

What is the force on a wire with a current of 5 amps, length of 5 cm, and magnetic flux density of 0.01 Tesla?

• 0.2 Newtons

• 2 Newtons

• 0.02 Newtons

• 0.002 Newtons

What is a key consideration when designing a powerful electric motor?

• Using the weakest magnets

• Using the shortest wire length

• Maximizing the number of wire loops

• Minimizing the current