A capacitor is made of two circular plates of radius R each, separated by a distance `d ltlt R`.The capacitor is connected to a constant voltage. A thin conducting disc of radius `r ltlt R` and thickness `t ltlt r` is placed at a centre of the bottom plate. find the minimum voltage required to lift the disc if the mass of hte disc is m.

A parallel plate capacitor (Fig. 8.7) made of circular plates each of radius R = 6.0 cm has a capacitance C = 100 pF. The capacitor is connected to a 230 V ac supply with a (angular) frequency of 300 rad s^-1 . What is the rms value of the conduction current? :

Figure shows a capacitor made of two circular plates each of radius 12 cm, and separated by 5.0 cm. The capacitor is being charged by an external source (not shown in the figure). The charging current is constant and equal to 0.15A. Obtain the displacement current across the plates. :

Fig.110 shows a capacitor made of two circular plates each of radius R=12 cm and separated by 5 cm.The capacitor is being charged by an external source (not shown in the figure).Use modified Ampere's circuital law to determine magnetic field at the point P at a distance of 0.5 m from the centre of the plats in the plane midway between them,when the chargingg current is 2A? .

A parallel plate capacitor (Fig. 8.7) made of circular plates each of radius R = 6.0 cm has a capacitance C = 100 pF. The capacitor is connected to a 230 V ac supply with a (angular) frequency of 300 rad s^-1 . Is the conduction current equal to the displacement current? :

Figure 8.6 shows a capacitor made of two circular plates each of radius 12 cm, and separated by 5.0 cm. The capacitor is being charged by an external source (not shown in the figure). The charging current is constant and equal to 0.15A. Calculate the capacitance and the rate of change of potential difference between the plates. :

Fig. TBQ 8.1 shows a capacitor made of two circular plates each of radius 12 cm, and separated by 5.0 cm. The capacitor is being charged by an external source (not shown in the figure). The charging current is constant and equal to 0.15 A. Calculate the capacitance and rate of change of potential difference between the plates.

A parallel plate capacitor (Fig. 8.7) made of circular plates each of radius R = 6.0 cm has a capacitance C = 100 pF. The capacitor is connected to a 230 V ac supply with a (angular) frequency of 300 rad s^-1 . Determine the amplitude of B at a point 3.0 cm from the axis between the plates. :

Figure 8.6 shows a capacitor made of two circular plates each of radius 12 cm, and separated by 5.0 cm. The capacitor is being charged by an external source (not shown in the figure). The charging current is constant and equal to 0.15A. Is Kirchhoffs first rule (junction rule) valid at each plate of the capacitor? Explain. :

A metal bar AB can slide on two parallel thick metallic rails separated by a distance l. A resistance R and an inductance L are connected to the rails as shown in the figure. A long straight wire carrying a constant current I_(0) is placed in the plane of the rails and perpendicular to them as shown. The bar AB is held at rest at a distance x_(0) from the long wire. At t=0, it is made to slide on the rails away from wire. Answer the following questions. Find a relation among i, (di)/(dt) and (d phi)/(dt) , where i is the current in the circuit and phi is the flux of the megnetic field due to the long wire through the circuit.

From a uniform disk of radius R, a circular hole of radius R//2 is cut out. The centre of the hole is at R//2 from the centre of the original disc. Locale the centre of gravity of the resulting flat body.