Which property of ferromagnetic materials makes them essential in electromagnetism?

• High electrical conductivity

• Ability to remain magnetized after exposure to a magnetic field

• Resistance to high temperatures

• Low magnetic permeability

How does the "Right-Hand Grip Rule" apply to a current-carrying conductor?

• Thumb points to magnetic north; fingers show current direction

• Fingers show current direction; thumb shows magnetic field

• Thumb points to magnetic north; fingers show electron flow

• Fingers indicate circuit voltage; thumb shows resistance

What is the purpose of a "contactor" in heavy-duty electrical circuits?

• To generate mechanical force

• To switch high current loads

• To regulate voltage

• To store magnetic energy

In an NC relay contact, what happens when the relay coil is energized?

• The circuit remains closed

• The contact opens, interrupting the circuit

• The magnetic field is strengthened

• The current flow increases

Why is a solenoid housing typically made of iron or steel?

• To reduce circuit impedance

• To prevent electrical interference

• To concentrate the magnetic field

• To provide insulation

Which factor directly influences the strength of the magnetic field in a solenoid?

• Material of the plunger

• Number of coil turns

• Length of the solenoid

• Ambient temperature

What is the main advantage of using Normally Open (NO) relay contacts in control circuits?

• They ensure the circuit is closed during failures

• They reduce current loss

• They remain off until a control signal is applied

• They provide continuous current flow

What is a permanent magnet?

• A magnet that loses strength over time

• A material that remains magnetized after being removed from a magnetic field

• A temporary magnetic material

• A conductor that generates a magnetic field

What direction do magnetic lines of flux move outside a magnet?

• South to North

• North to South

• Clockwise

• Randomly

Which rule helps determine the direction of a magnetic field in a current-carrying conductor?

• Fleming's Left-Hand Rule

• Right-Hand Grip Rule

• Ohm's Law

• Faraday's Law