A capacitor is connected to a battery. If a dielectric slab is introduced fully in the intervening space between the capacitor plates the electric field between the plates will
Decrease
Increase
Remain the same
cannot be answered from the data
Three capacitors of capacitance 3μF, 9μF and 18 μF are connected first in series and then in parallel. The ratio of the equivalent capacities in the two cases is
1:15
15:1
1:1
1:2
Two conducting spheres of radii 5cm and 3cm are equally charged.The ratio of the electric fields on their surfaces will be
3:5
5:3
9:25
25:9
The electric field at a certain point is 10NC-1.The electric lines of force crossing unit area around the point at right angles to it is
εo
1/εo
10
10/εo
In a charged capacitor the energy is stored
In the filed between the plates
In the positive charges
In the negative charges
On the plates
A copper slab of thickness d/2 is introduced between the plates of a parallel plate capacitor of plate separation d. If the capacitance of the capacitor without copper slab is c and with copper slab is c', then c '/c is
√2
2
1
1/√2
Two conducting spheres of radii 5cm and 3cm are charged so that the electric field on their surface are same.The ratio of the charges will be
A parallel plate capacitor is charged. If the plates of the capacitor are moved further apart by means of insulating handle without disconnecting the battery, then
capacitance increases
stored energy decreases
Voltage across the plates decreases
charge on the capacitor increases
A battery is used to charge a parallel plate capacitor till the potential difference between the plates becomes equal to the electromotive force of the battery. The ratio of the energy stored in the capacitor and the work done by the battery will be
1/4
1/2