CentreCourseYear/ TrimesterSession | : Centre for Foundation Studies (CFS): Foundation in Science: Year 1 / Trimester 2: 201210 | Unit CodeUnit TitleLecturer | : FHSC1024: Thermodynamics and Electromagnetism: Mr. Lim Min Leong Mr. Chua Lai Choy Ms. Nurfadzilah Ms. NorHabibiSaadah Mr. Koh Pin Wai Mr. Yam Si Kin |
Additional Tutorial 9: Magnetism
1. (a) What is the magnitude of the force per meter of length on a straight wire carrying an 8.40 A current when perpendicular to a 0.90 T uniform magnetic field? (b) What if the angle between the wire and field is 45.0°? [Answer: (a) 7.6 N m–1; (b) 5.3 N m–1]
2. A 1.5 m length of wire carrying 4.5 A of current is oriented horizontally. At that point on the Earth’s surface, the dip angle of the Earth’s magnetic field makes an angle of 38° to the wire. Estimate the magnitude of the magnetic force on the wire due to the Earth’s magnetic field of 5.5 × 10–5 T at this point. [Answer: 2.3 × 10–4 N]
3. A 5.0 MeV (kinetic energy) proton enters a 0.20 T magnetic field, in a plane perpendicular to the field. What is the radius of its path? [Answer: 1.6 m]
4. Determine the magnitude and direction of the force between two parallel wires 35 m long and 6.0 cm apart, each carrying 25 A in the same direction. [Answer: 7.3 × 10–2 N, attractive]
5. Calculate the force on an airplane which has acquired a net charge of 1550 µC and moves with a speed of 120 ms-1 perpendicular to the Earth’s magnetic field of 5.0 × 10–5 T. [Answer: 9.3 × 10–6 N]
6. Determine the magnetic field midway between two long straight wires 2.0 cm apart in terms of the current I in one when the other carries 15 A. Assume these currents are (a) in the same direction, and (b) in opposite directions. [Answer: (a) (2 × 10–5)(I – 15) T; (b) (2 × 10–5)(I + 15) T]
7. A circular coil of radius 2.0 cm has 100 turns. Its plane is kept in a vertical position and a small