The electrostatic force obeys _______.

(a)

Newton's I law

(b)

Newton's II law

(c)

Newton's III law

(d)

none of the above

The value of constant 'K' in coulomb law is _____________.

(a)

0.9 x 10⁹ Nm² C²

(b)

9 x 10^-9 Nm²C²

(c)

9 x 10⁹ Nm^-2 C^-2

(d)

9 x 10⁹ Nm² C^-2

The relative permittivity of water is _______.

(a)

ε_r = 70

(b)

ε_r = 75

(c)

ε_r = 80

(d)

ε_r = 85

The figure shows tow parallel equipotential surface A and B kept at a small distance 'r' a part from each other. A point change of Q coulomb is taken from the surface A to B. The amount of net work done will be 

(a)

\(W=\frac { -1 }{ 4\pi { \varepsilon }_{ 0 }r } \frac { q }{ r } \)

(b)

\(W=\frac { 1 }{ 4\pi { \varepsilon }_{ 0 }r } \frac { q }{ r } \)

(c)

\(W=\frac { -1 }{ 4\pi { \varepsilon }_{ 0 }r } \frac { q }{ r^2 } \)

(d)

zero

An uncharged metal sphere is placed between two equal and oppositely charged metal plates. The nature of lines of force will be ______________

(a)

(b)

(c)

(d)