Choose the correct alternative (a), (b), (c) or (d) for the question given below:
In the figure, a charge Q is fixed. another charge q s moved along a circular arc MN of radius r around it, from the point M to the point N such that the length of the arc MN = l. The work done in this process is:
zero
A.
zero
Work done in moving a charge between two points on an equipotential surface is zero.
Electrostatic potential energy stored in capacitor C3. (c) ‘n’ cells, each of emf ’e’ and internal resistance ‘r’ are joined in series to form a row. ‘m’ such rows are connected in parallel to form a battery of N = mn cells. This battery is connected to an external resistance ‘R’
(i) What is the emf of this battery and how much is its internal resistance?
(ii) Show that current ‘I’ flowing through the external resistance ‘R’ is given by :
Emf = ne
Equivalent Internal resistance = R'
V = V1 + V2 + V3 ...(i)
Q = i1V1 = i2V2 = i3V3 ---(ii)
In place of the above arrangement a single capacitor C equ is imagined which can withstand the applied P.D v and can store the same magnitude of charge Q.
Q =CequV ---(iii)
From Eq. (i) + Eq. (iii)
Q = Cequ (V1+V2+V3) ... (iv)
From Eq. (ii) + Eq. (iv)
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