AP EAMCET201921 Apr 2019Evening ShiftPhysicsElectromagnetic InductionActual
A coil of mean area 500 cm 2 and having 1000 turns is held with its plane perpendicular to a uniform field of 0 . 4 G . If the coil is turned through 180 ° in 1 10 second, then the average induced emf is 1 G = 10 - 4 T
Options
- A0 . 04   V
- B0 . 4   V
- C4   V
- D40   V
Correct answer
A. 0 . 04   V
Step-by-step solution
At time, Δ t = 1 10 = 0 . 1   s Coil turned from θ = 0 to 180 ° The expression for the change in flux is, Δ θ = θ f - θ Δ θ = N B A cos 180 ° - N B A cos 0 ° Δ θ = - 2 N B A The emf induced is, E = - Δ θ Δ t E = - - 2 N B A Δ t E = 2 N B A Δ t Substitute the values in the above equation. E = 2 × 1000 × 0 . 4 × 10 - 4 × 0 . 05 0 . 1 = 0 . 04   V