Paper 1 Magnetic Fields Drills

Q1

Magnetic field lines outside a bar magnet conventionally go from

A. south to north.
B. north to south.
C. east to west.
D. lower potential to higher potential.

Q2

A magnetic field is strongest where field lines are

A. widely spaced.
B. closest together.
C. straight only.
D. circular only.

Q3

The symbol $\odot$ represents a field or current

A. into the page.
B. out of the page.
C. to the left.
D. zero.

Q4

The symbol $\otimes$ represents a field or current

A. out of the page.
B. into the page.
C. upward.
D. clockwise.

Q5

Around a long straight wire, magnetic field lines are

A. radial lines.
B. concentric circles.
C. parallel straight lines along the wire.
D. ellipses ending on charges.

Q6

The direction of field around a current-carrying wire is found using

A. Fleming left-hand rule.
B. right-hand grip rule.
C. Snell law.
D. Kirchhoff law.

Q7

At fixed distance from a long straight wire, magnetic flux density is proportional to

A. $I$.
B. $1/I$.
C. $I^2$.
D. zero for direct current.

Q8

For a circular coil, the field near the centre is strengthened by increasing

A. number of turns.
B. resistance only.
C. temperature only.
D. coil colour.

Q9

A long solenoid has field lines inside that are approximately

A. radial.
B. uniform and parallel.
C. zero.
D. random.

Q10

Adding a soft iron core to a solenoid usually

A. weakens the field.
B. reverses current automatically.
C. strengthens the field.
D. makes field vanish.

Q11

The north pole of a solenoid is identified by current direction because viewed from that end the current is

A. clockwise.
B. anticlockwise.
C. zero.
D. alternating only.

Q12

Magnetic field lines form closed loops because

A. magnetic monopoles are isolated easily.
B. there are no isolated magnetic poles in this model.
C. charges stop moving.
D. field lines must cross.

Q13

In a uniform magnetic field diagram, field lines are drawn

A. parallel and equally spaced.
B. curved and crossing.
C. ending on positive charge.
D. randomly spaced.

Q14

Two parallel wires carrying currents in the same direction have magnetic fields between them that tend to

A. reinforce everywhere.
B. partly cancel between the wires.
C. be zero outside only.
D. be electric fields only.

Q15

A compass near a current-carrying wire aligns with

A. electric current direction only.
B. local magnetic field direction.
C. gravitational field only.
D. wire resistance.

Q16

A magnetic field can be produced by

A. stationary charges only.
B. moving charges or currents.
C. mass only.
D. temperature only.

Q17

Magnetic flux density is measured in

A. tesla.
B. farad.
C. ohm metre.
D. coulomb.

Q18

Field line arrows show

A. force on a positive electric charge at rest.
B. direction of magnetic field.
C. direction of electron drift only.
D. direction of heat flow.

Q19

Increasing solenoid current while keeping geometry fixed

A. increases field strength.
B. decreases field strength.
C. has no effect.
D. changes field to electric field.

Q20

For a straight wire, reversing current

A. does not affect field direction.
B. reverses the circular field direction.
C. removes the field.
D. makes field radial.