electromagnetic induction

What is Lenz's Law?

• Lenz's Law states that the direction of induced current is always such that it opposes the change in magnetic flux that produced it.

• Lenz's Law states that induced current flows in the same direction as the change in magnetic flux.

• Lenz's Law states that the induced current has no effect on the magnetic field.

• Lenz's Law states that the induced current is proportional to the rate of change of magnetic flux.

How does resistance affect induced current in a circuit?

• Higher resistance in a circuit reduces the induced current for a given induced voltage.

• Higher resistance increases the induced current for a given induced voltage.

• Resistance has no effect on the induced current in a circuit.

• Lower resistance increases the induced current but only at high voltages.

What is the direction of induced current when a magnet is moved towards a coil?

• The induced current flows in the same direction as the magnet's movement.

• The induced current flows in the opposite direction to the magnet's movement.

• The induced current flows in a direction that opposes the change in magnetic flux, according to Lenz's Law.

• The induced current does not flow at all when the magnet is moved.

What is the role of a transformer?

• A device that converts electrical energy into mechanical energy.

• A device that transfers electrical energy between two or more circuits through electromagnetic induction, typically used to increase or decrease voltage.

• A device that stores electrical energy for later use.

• A device that measures electrical current in a circuit.

What happens to the induced voltage if the number of coils in a wire increases?

• The induced voltage remains the same regardless of the number of coils.

• The induced voltage decreases as the number of coils increases.

• The induced voltage doubles when the number of coils doubles.

• The induced voltage increases but not in a predictable manner.

What happens to the induced voltage if the speed of the magnet's movement increases?

• The induced voltage decreases as the speed of the magnet's movement increases.

• The induced voltage remains constant regardless of the speed of the magnet's movement.

• The induced voltage increases as the speed of the magnet's movement increases, due to a greater rate of change of magnetic flux.

• The induced voltage fluctuates randomly with the speed of the magnet's movement.

What is the formula for calculating induced EMF?

• Induced EMF (ε) = -dΦ/dt, where Φ is the magnetic flux and t is time.

• Induced EMF (ε) = dΦ/dt, where Φ is the magnetic flux and t is time.

• Induced EMF (ε) = -Φ/t, where Φ is the magnetic flux and t is time.

• Induced EMF (ε) = -t/Φ, where Φ is the magnetic flux and t is time.

What is magnetic flux?

• The amount of electric charge passing through a surface per unit time.

• The product of the magnetic field strength and the area perpendicular to the field through which the field lines pass.

• The force experienced by a charged particle in a magnetic field.

• The total number of magnetic field lines passing through a given area.

What is the relationship between magnetic field strength and induced voltage?

• The induced voltage is inversely proportional to the magnetic field strength.

• The induced voltage is directly proportional to the rate of change of the magnetic field strength.

• The induced voltage is independent of the magnetic field strength.

• The induced voltage is proportional to the square of the magnetic field strength.

What is the significance of the left side of a coil in terms of magnetic polarity?

• The left side of a coil is always the south pole regardless of current direction.

• The left side of a coil can be designated as the north pole when current flows in a specific direction, based on the right-hand rule.

• The left side of a coil has no magnetic polarity.

• The left side of a coil is neutral and does not affect magnetic fields.