Chap#12 Electrostatics Flashcards
The force between two charges 0.06 m apart is 5N. If each charge is moved towards the other by 0.01 m, then the force between them will become:
11.25 N
Two point charge +3μC and +8μC repel each other with a force of 40N. If a charge of -5μC is added to each of them, then the force between them will become:
-10N
In a Millikan’s oil drop experiment the charge of an oil drop is calculated to be 6.35 x 10^-19 C. The number of excess electrons on the drop is:
4
A point charge Q is placed at the id-point of a line joining two charges, 4q and q. If the net force on charge q is zero, then Q must be equal to:
-q
Two point charges placed at distance of 20cm in air repel each other with a certain force. When a dielectric slab o thickness 8cm and dielectric constant K is introduced between these point charges, force of interaction becomes half of its previous value. Then K is approximately:
4
When a Na ion and a Cl ion are placed in air, a force F acts between them when they are separated by a distance of 1 cm from each other. The permittivity of air and the dielectric constant o water are ε and K respectively. When a piece of slat is placed in water, then the force between Na+ and Cl- ions separated by a distance of 1 cm will be:
F/K
The force of repulsio between two point charges is F, when these are at a distance 0.1m apart. Now the point charges are replaced by spheres of radii 5 cm each having the same charges as that of the respective point charges. The distance between their centre is again kept 0.1 m ; then the force of repulsion will:
Remain F
A charge Q is divided into two parts q and Q - q and separated by a distance R. The force of repulsion between them will be maximum when:
q = Q/2
Two point charges A and B seprated by a distance R attract each other with a force of 12 x 10^-3 N. The force between A and B when the charges on them are doubled and distance is halved.
0.192 N
