A solenoid has 2000 turns wound over a length of 0.30 m . The area of its cross-section is 1.2 × 10-3 m2. Around its central section, a coil of 300 turn is wound. If an initial current of 2A in the solenoid is reversed in 0.25 s, then the emf induced in the coil is

Question

A solenoid has 2000 turns wound over a length of 0.30 m . The area of its cross-section is 1.2 × 10-3 m2. Around its central section, a coil of 300 turn is wound. If an initial current of 2A in the solenoid is reversed in 0.25 s, then the emf induced in the coil is (A) 6 × 10-4 V (B) 4.8 × 10-3 V (C) 6 × 10-2 V (D) 48 mV

Tardigrade Admin · Accepted Answer

Induced emf e=M (di/dt) =(μ0 N1 N2 A/l). (di/dt) =(4π×10-7×2000×300×1.2×10-3/0.30) ×(|2-(-2)|/0.25) =48.2×10-3 V=48 mV

Q. A solenoid has $2000$ turns wound over a length of $0.30 m$ . The area of its cross-section is $1.2 \times 1 0^{- 3} m^{2}$ . Around its central section, a coil of $300$ turn is wound. If an initial current of $2 A$ in the solenoid is reversed in $0.25 s$ , then the emf induced in the coil is

$6 \times 1 0^{- 4} V$

$4.8 \times 1 0^{- 3} V$

$6 \times 1 0^{- 2} V$

$48 mV$

Induced emf $e = M \frac{d i}{d t}$
$= \frac{μ _{0} N _{1} N _{2} A}{l} . \frac{d i}{d t}$
$= \frac{4 π \times 1 0 ^{- 7} \times 2000 \times 300 \times 1.2 \times 1 0 ^{- 3}}{0.30}$
$\times \frac{∣ 2 - ( - 2 ) ∣}{0.25}$
$= 48.2 \times 1 0^{- 3} V = 48 mV$

Q. A solenoid has 2000 turns wound over a length of 0.30m . The area of its cross-section is 1.2×10−3m2. Around its central section, a coil of 300 turn is wound. If an initial current of 2A in the solenoid is reversed in 0.25s, then the emf induced in the coil is

6×10−4V

4.8×10−3V

6×10−2V

48mV