Physics Quiz: Magnetic Fields and Induction

Who were the two physicists that independently discovered that magnetic fields can induce electric currents?

• Isaac Newton and Albert Einstein

• Joseph Henry and Michael Faraday

• Marie Curie and Galileo Galilei

• Nikola Tesla and Thomas Edison

What is the property that most directly induces emf in a loop of wire?

• Magnetic Flux

• Electric Resistance

• Gravitational Force

• Thermal Conductivity

What is the unit of measurement for magnetic flux?

• Webers

• Joules

• Tesla

• Ohms

According to Faraday's Law of Induction, when does a changing magnetic field induce an emf in a loop of wire?

• When the loop area is constant

• When the angle between the loop and the magnetic field is constant

• When the magnetic field is constant

• When the magnetic field is changing with time

What is the formula to calculate the induced emf in a coil of wire?

• emf = B x A x cos(theta)

• emf = N x (change in flux / change in time)

• emf = L x v x B

• emf = -d(flux) / dt

In Lenz's Law, what is the direction of the magnetic field generated by the induced current in relation to the change in magnetic flux?

• Opposite direction

• Random direction

• Same direction

• Perpendicular direction

How can a change in magnetic flux be induced by moving a loop of wire out of a magnetic field?

• By changing the width of the loop within the magnetic field

• By changing the angle of the loop

• By changing the length of the loop

• By changing the strength of the magnetic field

What is the role of the head in a hard drive when it comes to inducing a current?

• It generates a magnetic field

• It stores digital information

• It has a coil of wire that induces a current

• It rotates the disk

What is the purpose of magnetizing small sections of the disk in a hard drive?

• To store digital information

• To decrease the speed of the disk

• To increase the weight of the disk

• To cool down the disk

How does a computer read information stored on a hard drive?

• By rotating the disk past the head

• By increasing the magnetic field strength

• By changing the area of the loop

• By altering the angle between the loop and the magnetic field