Question
Physics 2
Answer as many as you know please
15. A circular coil of wire having 200 turns and diameter 2.0 cm carries a current of 4.0 A. This current loop is placed in a uniform magnetic field of 0.70 T, with the axis of the coil making an angle of 60 with the magnetic field. Find the magnitude of the torque that the magnetic field exerts on the loop. A) 0.15 N.m B) 0.40 N.m C) 0.76 N.m D) 0.088 N.m E) 0.29 N.nm 16. A long, solid wire conductor has radius R 10 mm. The wire carries a current of 3.0 A which is uniformly distributed over the cross-section of the wire (current density is constant). What is the magnitude of the magnetic field due to the current in the wire at a radial distance of r3 mm from the central axis of the wire (inside the wire)? Hint: Ampere's Law can help. A) 20 HT C) 12 HT D) 30 HT
Explanation / Answer
Torque of circular wire due to magnetic field is given as
T = BINAcos(?)
B = Magnitude of the magnetic field
I = Current in the coil
N = Number of turns in the coil
A = Cross-sectional area of the conductor
? = Angle between the coil and the magnetic field
T = (0.7)(4)(200)?(0.02/2)²cos(60°)
T = 0.088 N•m <==============