8T.4.4 Electricity and Magnetism Quiz for 8th Grade

A wire carrying current is placed in a magnetic field. How would you determine the direction of the force acting on the wire?

• Use the left-hand rule
• Use the right-hand rule
• Calculate the cross product of current and magnetic field
• Measure the wire's resistance

Tags

NGSS.HS-PS3-5

Why does a loop of wire carrying current in a magnetic field behave differently from a straight wire?

• The loop has more resistance
• The loop creates a stronger magnetic field
• The loop experiences forces in different directions, causing rotation
• The loop cancels out the external magnetic field

Tags

NGSS.HS-PS3-5

In an electric motor, what principle is responsible for the continuous rotation of the armature?

• Electromagnetic induction
• Commutation
• Magnetic repulsion
• Electrical resistance

Tags

NGSS.HS-PS3-5

How does electromagnetic induction relate to the conservation of energy?

• It violates energy conservation
• It converts mechanical energy to electrical energy
• It creates energy from nothing
• It only works with magnetic energy

Why is alternating current (AC) preferred for long-distance power transmission over direct current (DC)?

• AC is easier to generate
• AC can be easily transformed to different voltages
• AC has less energy loss
• AC is safer to use

How does a step-up transformer increase voltage?

• By increasing current in the primary coil
• By using a stronger magnetic core
• By having more turns in the secondary coil than the primary
• By rotating the coils faster

What would happen to the current induced in a conductor if it moves through a magnetic field at twice the speed?

• The current would double
• The current would halve
• The current would remain the same
• The current would become zero

Tags

NGSS.HS-PS2-5

NGSS.HS-PS3-5