The best description of the two charges is that the

• charges are both positive.

• charges are both negative.

• charges can be either both positive or both negative.

• left-hand charge is positive and the right-hand charge is negative.

Jupiter’s moon Ganymede is its largest satellite. Ganymede has a mass of 1.5 × 10²³ kg and a radius of 2.6 × 10⁶ m. Which one of the following is closest to the magnitude of Ganymede’s surface gravity?

•  0.8 m s⁻²

•  1.5 m s⁻²

• 3.8 m s⁻²

• 9.8 m s^-2

Which one of the following best gives the speed of the positron as it exits the magnetic field?

• 0 m/s

• much less than 1.4 × 10⁶ m/s

•  1.4 × 10⁶ m/s

• greater than 1.4 × 10⁶ m/s

The speed of the positron is changed to 7.0 × 10⁵ m/s. Which one of the following best gives the value of the radius r for this speed?

• r/4

• r/2

• r

• 2r

A coil consisting of 20 loops with an area of 10cm² is placed in a uniform magnetic field of strength 0.03T so that the plane of the coil is perpendicular to the field direction. The magnetic flux through the coil is closest to

• 0 Wb

•  3.0 × 10⁻⁵ Wb

• 6.0 × 10⁻⁴ Wb

• 3.0 × 10⁻¹ Wb

A single loop of wire moves into a uniform magnetic field B of strength 3.5x10^-4 T over time t = 0.20 s from point X to point Y. The area of the loop is 0.05 m² The magnitude of the average induced EMF in the loop is closest to

• 0 V

• 3.5 × 10⁻⁶ V

• 8.8 × 10⁻⁵ V

• 8.8 × 10³ V

An ideal transformer has an input DC voltage of 240 V, 2000 turns in the primary coil and 80 turns in the secondary coil. The output voltage is closest to

• 0 V

• 9.6 V

• 6.0 × 10³ V

• 3.8 × 10⁷ V

The arrows in option E below, indicate the direction and the size of the forces acting on the ball (A. to D). Ignoring air resistance, which one of the following (A-D) best represents the forces acting on the ball when it is at the bottom of the circular path and moving to the left?

• A

• B

• C

• D

• 

Two blocks of mass 5 kg and 10 kg are in contact on a frictionless surface. The force F is applied tot he 5kg block as shown. Which one of the following statements is correct?

• The net force on each block is the same.

• The acceleration experienced by the 5 kg block is twice the acceleration experienced by the 10 kg block.

• The magnitude of the net force on the 5 kg block is half the magnitude of the net force on the 10 kg block.

• The magnitude of the net force on the 5 kg block is twice the magnitude of the net force on the 10 kg block.

If the force F has a magnitude of 250 N, what is the work done by the force in moving the blocks in a straight line for a distance of 20 m?

• 5 kJ

• 25 kJ

• 50 kJ

• 500 kJ