Electricity & Motor

What happens when current flows through a wire?

• a) A device that produces sound
• b) A substance that attracts iron
• c) A type of battery
• d) A form of light

Answer explanation

Current creates a circular magnetic field

The Right Hand Grip Rule is used to determine:

• a) It produces light
• b) It produces a magnetic field
• c) It cools down
• d) Nothing happens

Answer explanation

Thumb = current, fingers = field direction.

If current flows towards you, the magnetic field lines are:

• a) Clockwise
• b) Counter-clockwise
• c) Straight
• d) Non-existent

Answer explanation

Right-hand rule for current toward observer.

A solenoid is:

• a) A single straight wire
• b) A coil of wire
• c) A type of battery
• d) A magnet

Answer explanation

Solenoids are helical coils that amplify magnetic fields.

Why does a solenoid act like a magnet when current flows?

• a) Because it has iron inside
• b) Because the coiled wire strengthens the magnetic field
• c) Because it produces light
• d) Because it has no resistance

Answer explanation

Coiling concentrates the field lines.

What happens if two parallel wires carry current in the same direction?

• a) They repel
• b) They attract
• c) They explode
• d) Nothing happens

Answer explanation

Same-direction currents create aligned fields that attract.

How can you increase the strength of a solenoid’s magnetic field?

• a) Use thinner wire
• b) Add an iron core
• c) Decrease the current
• d) Uncoil the wire

Answer explanation

Iron enhances magnetic permeability.

What does the Right Hand Grip Rule help determine?

• a) Current direction
• b) Magnetic field direction around a wire
• c) Voltage drop
• d) Resistance

Answer explanation

The rule links current and field direction.

If current in a wire flows away from you, the magnetic field direction is:

• a) Clockwise
• b) Counter-clockwise
• c) Upwards
• d) Downwards

Answer explanation

Current away = clockwise field (right-hand rule).

Why do two parallel wires with opposite currents repel?

• a) Their magnetic fields cancel out
• b) Their magnetic fields add up in the same direction
• c) They produce heat
• d) They stop conducting current

Answer explanation

Opposite currents create opposing fields between wires.