Electro Magnetic Induction And Alternating Currents Question 459
A square loop with 2.0 m sides is perpendicular to a uniform magnetic field, with half the area of the loop in the field. The loop contains a 20.0 V battery with negligible internal resistance. If the magnitude of the field varies with time according to B = 0.042-0.871t, with B in tesla and t in second. The net emf of the circuit is:
Options:
A) $ 20.0,V $
B) $ 18.26,V $
C) $ 21.74,V $
D) None of these
Show Answer
Answer:
Correct Answer: C
Solution:
- Induced emf. $ | \mathcal{E} | =\frac{d\phi }{dt}=A\left( \frac{dB}{dt} \right) $
$ =\frac{2\times 2}{2}\times \frac{d}{dt}(0.042-0.87t)=2\times (-0.87)= -1.74V $
The net induced emf $ =20+1.74=21.74\,V $
BETA
