Which of the following is correct ?
Joule = Coulomb x volt
Joule = Coulomb /volt
Joule = volt/ampere
Joule= volt/metre
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
zero
10v
same as at a point 10cm away from the surface
same as at a point 25cm away from the surface
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
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
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
11 v/m
Vandegreff generator is used for :
Charging of batteries
Checking voltmeter markings
Producing very high magnetic fields
Accelerating charged particles
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
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 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
