Physics

1. 1.

   A straight wire of length 0.150 m carries 4.00 A perpendicular to a uniform 0.200 T field. Calculate magnetic force and state its direction relative to current and field.

   [3 marks]
2. 2.

   A flat loop of area 0.0200 m^2 is in a 0.300 T uniform field. Its normal is 60.0 degrees to the field. Find flux through the loop.

   [3 marks]
3. 3.

   A proton moves at 2.00e6 m s^-1 perpendicular to a 0.500 T field in vacuum. Find its circular radius and explain why speed stays constant. Use m = 1.67e-27 kg and q = 1.60e-19 C; neglect relativistic effects.

   [3 marks]
4. 4.

   Flux through each turn of a 200-turn coil decreases uniformly from 0.00600 Wb to 0.00100 Wb in 0.0500 s. Find induced emf magnitude. Explain Lenz's law for the induced current if the circuit is closed.

   [3 marks]
5. 5.

   Parallel rails are 0.400 m apart. A conducting rod spans them perpendicularly and slides along them at 3.00 m s^-1, with the rod perpendicular to its motion. A uniform 0.500 T field is normal to the rail plane. The closed circuit has total resistance 2.00 ohm. Find emf, current, magnetic drag and external power for constant speed. Neglect friction and self-inductance.

   [3 marks]
6. 6.

   A 100-turn coil of area 0.0100 m^2 rotates uniformly at 50.0 Hz in a uniform 0.200 T field about a fixed axis in the coil plane and perpendicular to the field. Its normal aligns with the field at t = 0. Find peak emf, rms emf and the first positive time of peak magnitude. Neglect losses; give 3 significant figures.

   [3 marks]

Original, unofficial practice questions from SubjectScout — not official past-paper questions.