Which of the following is correct ?
Joule = Coulomb x volt
Joule = Coulomb /volt
Joule = volt/ampere
Joule= volt/metre
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
The ratio of the capacitance of a capacitor with a material filled in the entire space between the plates to the capacitance of the same capacitor with empty space in between the plates is equal to
∈0
∈
∈0∈r
∈r
When a capacitor of capacitance 4 F and p.d. 100v is dischrged, the energy released in joules will be :
0.2
0.02
0.04
0.05
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
A 500μF capcitor is charged at a steady rate of 100 c/s. The potential difference across the capacitor will be 10v after an interval of :
9s
20s
25s
50s
The electric potential V as a function of distance x in metres is given by V= (5x2-10x-9) volt. Calculate the value of electric filed at x= 1m ?
20 v/m
6 v/m
zero
11 v/m
Six metallic plates each of surface area of one side A are placed at a distance d from each other. The alternate plates are connected to P and Q. The capacitance of the system between P and Q will be :
∈0A/d
3∈0A/d
5∈0A/d
6∈0A/d
A hollow metal sphere of radius 5cm is charged such that the potential on its surface is 10v. The potential at the centre of the sphere is
10v
same as at a point 10cm away from the surface
same as at a point 25cm away from the surface
