A 500μF capcitor is charged at a steady rate of 100μc/s. The potential difference across the capacitor will be 10v after an interval of
9s
20s
25s
50s
Two charged bodies carrying +Q and -Q charges are attached one at each end to a spring of released length L and spring constant K.If the subsequent length of the spring is L then the condition for equilibrium is
Q2=4πεok(L'-L)L2
Q2=4πεok(L'-L)L
Q2=4πεok(L'-L)L'2
Q2=4πεok(L-L')L'2
1000 small water drops each of radius r and charge q coalesce to form one spherical drop. The potential of the big drop is larger than that of smaller one by a factor
1000
100
10
1
Two conducting spheres of radii 5cm and 3cm are charged to the same potential. The ratio of their charges will be
3:5
5:3
9:25
25:9
The radius of hydrogen atom is 5*10-11 m and the charge on electron or proton is of magnitude 1.6*10-11 c. At ground state,the dipole moment of the atom is
8*10-30cm
16*10-30cm
0 cm
4*10-30cm
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
An isolated metal sphere of radius R is given a charge q. its potential energy will be
q2/ 4π∈0R
q/ 4π∈0R
q/ 8π∈0R
q2/ 8π∈0R
The unit of electric field is
volt*metre
volt/joule
volt*joule
volt/metre
The kinetic energy of an electron accelerated through a potential of 100x is
1.6x10-17 J
1.6x1017 J
1.6x10-19 J
100J
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
2
1/4
1/2
