AP EAMCET202125 Aug 2021Evening ShiftPhysicsElectromagnetic InductionActual
A solenoid has 2000 turns wound over a length of 0.30 ~m . The area of its cross-section is 1.2 10⁻³ ~m . 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 , the emf induced in the coil is equal to
Options
- A6 10⁻⁴ ~V
- B4.8 10⁻² ~V
- C6 10⁻² ~V
- D48 10^3 ~V
Correct answer
B. 4.8 10⁻² ~V
Step-by-step solution
Given, aligned N₁ & =2000 L & =0.30 ~m N₂ & =300 aligned d i d t = 2-(-2) 0.25 = 4 0.25 As ⁻¹ aligned & A=1.2 10⁻³ ~m ^2 & Emf induced, e= M d i d t = ₀ N₁ N₂ A L d i d t & e= 4 10⁻⁷ 2000 300 1.2 10⁻³ 0.30 4 0.25 & =4.8 10⁻² ~V aligned