Question

If the emf (ɛ) of a coil rotating in a magnetic field is zero at t = 0, and increases to its first peak at t = 0.100 ms, what is the angular velocity (w) of the coil?

a) 2.5 × 104 rad/s
b) 5.0 × 104 rad/s
c) 1.0 × 105 rad/s
d) 2.0 × 105 rad/s

Answer 1

The angular velocity (w) of the coil can be found using the formula w = 2π/T, where T is the period. In this case, the emf of the coil increases to its first peak at t = 0.100 ms. This means that the period is equal to 0.100 ms. Therefore, the angular velocity of the coil is approximately 1.0 × 10^5 rad/s.

Step-by-step explanation:

The angular velocity (w) of the coil can be found using the formula w = 2π/T, where T is the period. In this case, the emf of the coil increases to its first peak at t = 0.100 ms. This means that the period is equal to 0.100 ms. Converting this period to seconds, we get T = 0.0001 s.

Plugging this value into the formula, we get w = 2π/0.0001 ≈ 62,831 radians per second. Therefore, the correct answer is option C) 1.0 × 10^5 rad/s.