Inv5.Exp3 Text B

According to Lenz's law, what does the negative sign in Faraday's law indicate?

• The induced current flows in the same direction as the change in flux
• The induced current and magnetic field oppose the change in flux
• The induced current is directly proportional to the change in flux
• The induced current has no relationship to the change in flux

When a magnet is pulled away from a wire loop, what happens to the external magnetic field?

• It remains constant
• It increases in strength
• It gets smaller
• It reverses direction

Which law helps determine the direction of both the induced magnetic field and current?

• Ohm's Law
• Coulomb's Law
• Biot-Savart Law
• Lenz's Law

How can magnetic flux be changed without moving a magnet?

• By changing the temperature of the wire
• By changing the wire's resistance
• By changing the area of the wire loop
• By changing the wire's material

In a setup with two metal rails, what factors affect the size of the induced EMF?

• Only the magnetic field strength
• Only the speed of the moving bar
• Only the distance between rails
• All of the above factors combined

What does an area vector represent in electromagnetic induction?

• The direction of current flow only
• The magnitude and direction perpendicular to the area
• The strength of the magnetic field only
• The resistance in the circuit

When using a solenoid instead of a permanent magnet, how can the external field be varied?

• By changing the supplied current
• By changing the wire thickness
• By changing the air temperature
• By changing the wire material

What is alternating current (AC)?

• Current that flows in one direction only
• Current that maintains constant magnitude
• Current that periodically reverses direction and changes magnitude
• Current that flows in parallel circuits only

What is required for wireless induction between two solenoids?

• Both solenoids must be supplied with current
• The solenoids must be touching
• Only one solenoid needs current supply
• The solenoids must be made of different materials

How does the magnetic field produced by a solenoid relate to the current supplied?

• It is inversely proportional
• It is proportional
• There is no relationship
• It varies randomly