Single Choice

The magnetic flux linked with a coil,in webers,is given by the equations $$ \phi = 3t^ 2+ 4t + 9 $$. Then the magnitude of induced e. m. f. at t = 2 second will be:

A2 volt
B4 volt
C8 volt
D16 volt
Correct Answer

Solution

Given that

Total magnetic flux $$\phi =3{{t}^{2}}+4t+9$$

We know that,

The induced e .m. f

$$ e=|\dfrac{-d\phi }{dt}| $$

$$ e=\dfrac{d\left( 3{{t}^{2}}+4t+9 \right)}{dt} $$

$$ e=6t+4 $$

Now, the induced e.m.f at $$t= 2$$ sec

$$ e=6\times 2+4 $$

$$ e=16\,volt $$

Hence, the magnitude of induced e.m.f is $$16 \ volt$$


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