Magnetic Effects of Electric Current Quiz

What happens to the compass needles when placed around a current-carrying wire?

• They point towards the nearest magnetic pole.

• They align with the magnetic field created by the current.

• They spin randomly due to the current.

• They remain unaffected by the current.

How does reversing the current direction affect the magnetic field around a wire?

• The magnetic field strengthens.

• The magnetic field disappears.

• The magnetic field weakens.

• The magnetic field's direction reverses.

What is the effect of coiling a wire into an inductor?

• It weakens the magnetic field.

• It has no effect on the magnetic field.

• It creates a uniform magnetic field.

• It strengthens and concentrates the magnetic field.

How do vector addition principles apply to magnetic fields in an inductor?

• They have no effect on the magnetic fields.

• They cancel out the magnetic fields.

• They create a new magnetic field.

• They combine to form a resultant field.

What happens to the magnetic flux in an inductor when the current increases?

• The magnetic flux disappears.

• The magnetic flux remains constant.

• The magnetic flux increases.

• The magnetic flux decreases.

According to Faraday's law, what does a time-varying magnetic flux generate?

• A time-varying magnetic field.

• A time-varying electric current.

• A constant electric current.

• A constant magnetic field.

What effect does the solenoid's magnetic field have on nearby nails?

• It causes them to spin.

• It has no effect.

• It attracts them.

• It repels them.

What is the mathematical expression for magnetomotive force (MMF)?

• MMF = n + i

• MMF = n / i

• MMF = n * i

• MMF = n - i

What does the number of turns in a coil affect?

• The color of the magnetic field.

• The temperature of the coil.

• The strength of the magnetic field.

• The direction of the magnetic field.

What is the purpose of winding a coil into a helix in a solenoid?

• To increase electrical resistance.

• To produce a magnetic field.

• To reduce electrical resistance.

• To change the color of the wire.