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In Fig. a uniform magnetic field decreas...

In Fig. a uniform magnetic field decrease at a constant rate `dB//dt = K`, where `K` is a positive constant. Circular loop of wire of radius a containing a resistnce `R` and a capacitnce `C` is placed with its plane normal to the field.
a. Find the charge `Q` on the capacitor when it is fully charged.
b. Which plate is at higher potential when it is fully charged?

Text Solution

Verified by Experts

The correct Answer is:
`pia^(2) CK`; b. The upper plate of capacitor is at a heigher potential.
a. `phi = pia^(2) B`
`varepsilon = (d phi)/(dt) = pia^(2) (dB)/(dt) rArr varepsilon = pia^(2) K`
When capacitor is fully charged, charge on capacitor is
`Q = C varepsilon`
`Q = pia^(2) CK`
b. The upper plate of capacitor is at a higher potential.
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