A solenoid has text2000 turns wound over a length of text0 text.30 m . The area of its cross section is 1.2× 10- 3 m2 . Around its central section, a coil of text300 turns is wound. If an initial current of text2 A in the solenoid is reversed in text0 text.25 s , then the emf induced in the coil is equal to

Question

A solenoid has text2000 turns wound over a length of text0 text.30 m . The area of its cross section is 1.2× 10- 3 m2 . Around its central section, a coil of text300 turns is wound. If an initial current of text2 A in the solenoid is reversed in text0 text.25 s , then the emf induced in the coil is equal to (A) 8.6× 10- 2V (B) 4.8× 10- 2V (C) 1.2× 10- 2V (D) 6.0× 10- 2V

Tardigrade Admin · Accepted Answer

E m f = (M d i/d t) = (((μ )0 N1 N2 A/l)) (d i/d t) = (4 π × (10)- 7 × 2000 × 300 × 1.2 × (10)- 3 (4)/0.3 × 0.25) =4.8 × 10- 2 V

$8.6 \times 1 0^{- 2} V$

$4.8 \times 1 0^{- 2} V$

$1.2 \times 1 0^{- 2} V$

$6.0 \times 1 0^{- 2} V$

$E m f = \frac{M d i}{d t} = (\frac{( μ ) _{0} N _{1} N _{2} A}{l}) \frac{d i}{d t}$
$= \frac{4 π \times ( 10 ) ^{- 7} \times 2000 \times 300 \times 1.2 \times ( 10 ) ^{- 3} ( 4 )}{0.3 \times 0.25}$
$= 4.8 \times 1 0^{- 2}$ V

Q. A solenoid has 2000 turns wound over a length of 0.30 m . The area of its cross section is 1.2×10−3m2 . Around its central section, a coil of 300 turns 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 equal to

8.6×10−2V

4.8×10−2V

1.2×10−2V

6.0×10−2V

Emf=dtMdi​=(l(μ)0​N1​N2​A​)dtdi​ =0.3×0.254π×(10)−7×2000×300×1.2×(10)−3(4)​ =4.8×10−2 V

$8.6 \times 1 0^{- 2} V$

$4.8 \times 1 0^{- 2} V$

$1.2 \times 1 0^{- 2} V$

$6.0 \times 1 0^{- 2} V$

$E m f = \frac{M d i}{d t} = (\frac{( μ ) _{0} N _{1} N _{2} A}{l}) \frac{d i}{d t}$
$= \frac{4 π \times ( 10 ) ^{- 7} \times 2000 \times 300 \times 1.2 \times ( 10 ) ^{- 3} ( 4 )}{0.3 \times 0.25}$
$= 4.8 \times 1 0^{- 2}$ V