A coil has 200 turns and area of 70 cm2 . The magnetic field perpendicular to the plane of the coil is 0.3 Wb m- 2 and takes 0.1 s to rotate through 180° . The value of the induced E.M.F. will be

Question

A coil has 200 turns and area of 70 cm2 . The magnetic field perpendicular to the plane of the coil is 0.3 Wb m- 2 and takes 0.1 s to rotate through 180° . The value of the induced E.M.F. will be (A) 8.4 V (B) 84 V (C) 42 V (D) 4.2 V

Tardigrade Admin · Accepted Answer

Induced EMF is, E=-N(Δ φ/Δ t) E=(- N B A (cos (θ )2 - cos â¡ (θ )1)/Δ t) E=-(N B A (cos 1 (80)o - (cos)o â¡ 0)/Δ t) E=(2 N B A/t) E=(2 (200) (0.3) (70 × 1 0- 4)/0.1) E=8.4 V

Q. A coil has $200$ turns and area of $70 c m^{2}$ . The magnetic field perpendicular to the plane of the coil is $0.3 Wb m^{- 2}$ and takes $0.1 s$ to rotate through $18 0^{\circ}$ . The value of the induced E.M.F. will be

$8.4 V$

$84 V$

$42 V$

$4.2 V$

Induced $EMF$ is,
$E = - N \frac{Δ ϕ}{Δ t}$
$E = \frac{- NB A ( cos ( θ ) _{2} - cos ( θ ) _{1} )}{Δ t}$
$E = - \frac{NB A ( cos 1 ( 80 ) ^{o} - ( cos ) ^{o} 0 )}{Δ t}$
$E = \frac{2 NB A}{t}$
$E = \frac{2 ( 200 ) ( 0.3 ) ( 70 \times 1 0 ^{- 4} )}{0.1}$
$E = 8.4 V$

Q. A coil has 200 turns and area of 70cm2 . The magnetic field perpendicular to the plane of the coil is 0.3Wbm−2 and takes 0.1s to rotate through 180∘ . The value of the induced E.M.F. will be

8.4V

84V

42V

4.2V