Electro Magnetic Induction And Alternating Currents Question 403
Question: If a coil of 40 turns and area 4.0 cm2 is suddenly removed from a magnetic field, it is observed that a charge of $ 2.0\times {{10}^{-4}}C $ flows into the coil. If the resistance of the coil is $ 80\Omega $ , the magnetic flux density in $ Wb/m^{2} $ is [MP PET 2005]
Options:
A) 0.5
B) 1.0
C) 1.5
D) 2.0
Show Answer
Answer:
Correct Answer: B
Solution:
$ \Delta Q=\frac{\Delta \varphi }{R}=\frac{n\times BA}{R} $
Þ $ B=\frac{\Delta Q.R}{nA} $ $ =\frac{2\times {{10}^{-4}}\times 80}{40\times 4\times {{10}^{-4}}} $ $ =1\ Wb/m^{2} $
