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A parallel plate capacitor has plate area 25.0 cm2 and a separation of 2.0 mm between the plates. The capacitor is connected to a battery of 12.0 V (a) Find the charge on the capacitor (b) The plate separation is decreased to 1.00 mm. Find the extra charge given by the battery to the positive plate.
Figure shows a network of capacitors where the numbers indicate the capacitances in microfarad. Find the value of capacitance C if the equivalent capacitance between A and B is to be 2μF.
Figure a show the field lines of a single positive and negative charge respectively.
(a) Give the signs of potential difference (VP – VQ) and (VB – VA).
(b) Give the sign of potential energy difference of a small negative charge between the points Q and P; A and B.
(c) Give the sign of the work done by the field in moving a small positive charge from Q to P.
(d) Give the sign of the work done by external energy in moving a small negative from B to A.
(e) Does the kinetic energy of a small negative charge increase in going B to A?
In figure the values of capacitances are as follows:
C1 = C2 = C3 = C4 = 4μF, C5=5μF.
Calculate the equivalent capacitance between the points P and Q. If a battery of 10 volt is connected between these points, what will be the charge on each capacitor?
A spherical conducting shell of inner radius r1 and outer radius r2 has a charge Q.
(a) Show that the field inside the cavity is zero.
(b) A charge q is placed at the centre of the shell. What is the surface charge density on the inner and outer surfaces of the shell?
(c) Is the electric field inside a cavity (with no charge) zero, even if the shell is not spherical; but has any irregular shape? Explain.
The area of each plate of parallel plate air capacitor is 150 cm2. The distance between its plates is 0.8 mm. It is charged to a pot. Difference of 1200 volt. What will be its energy? What will be the energy when it is filled with a medium of K = 3 and then charged. If it is charged first as an air capacitor and then filled with this dielectric, what will happen to energy?
A metal sphere A of radius a is charged to potential V. What will be its potential if it is enclosed by a spherical conducting shell B of radius b and the two are connected by a wire?
An infinite number of charges each numerically equal to q and of the same sign are placed along the x-axis at x = 1, x = 2, x = 4, x = 8 and of on. Find electric potential at x = 0
Two particles have equal masses of 5.0 g each and opposite charges of +4.0×10–5C and –4.0×10–5C. They are released from rest with a separation of 1.0 m between them. Find the speeds of the particles when the separation is reduced to 50 cm.
Four-point charges +1μC, +1μC, -1μC and -1μC are placed at the corners A, B, C and D of a square of each side 0.1 m
(i) Calculate electric potential at the centre O of the square
(ii) If E is middle point of BC, what is work done in carrying an electron from O to E?