Question

Which one of the following can produce the maximum induced e.m.f? [1]

a. 50A, DC

b. 50A, 50 HzAC

c. 50A, 500 HzAC

d.100A, DC​

Answer 1

Explanation:

A 50 A, 500 Hz AC will produce maximum induced emf due to high frequency.

hope it helps you

Answer 2

Answer:

See below.

Explanation:

As alternating currents produce alternating magnetic flux through a wire loop the value of  

$\dfrac{d\Phi _{B}}{dt}$

will be higher as the current is changing it's direction periodically. As the magnetic field produced by a straight wire depends on the current, the magnetic field changes continuously.

So, options A and D are ruled out.

Now, a flux produced by a 50 Hz AC current will produce a relatively less changing magnetic field, as the frequency of the current is less. A 500 Hz AC current will oscillate 500 times a second and hence the change in flux will be greater. And as we know,

$\epsilon \propto \dfrac{d\phi _{B}}{dt}$

Therefore option C is correct whose frequency is more.