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

The given figure is a plot of lines of force due to two charges q₁ & q₂ find out the sign of charges

(a)

both negative

(b)

both positive

(c)

upper positive and lower negative

(d)

upper negative and lower positive

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)

An isolated metal sphere of radius 'r' is given a charge' q'. The potential energy of the sphere is ____________

(a)

\(\frac { { q }^{ 2 } }{ 4\pi { \varepsilon }_{ 0 }r } \)

(b)

\(\frac { { q }^{ } }{ 4\pi { \varepsilon }_{ 0 }r } \)

(c)

\(\frac { { q }^{ } }{ 8\pi { \varepsilon }_{ 0 }r } \)

(d)

\(\frac { { q }^{ 2 } }{ 8\pi { \varepsilon }_{ 0 }r } \)

In a hydrogen atom the electron revolves around the proton in an orbit of 0.53 \(\mathring { A } \). The potential produced by the electron on the nuleus is ___________

(a)

6.8 V

(b)

13.6 V

(c)

54.4 V

(d)

27.2 V

Eight mercury droplets having a radius of 1 mm and charge of 0.066 PC each merge to form one droplet. Its potential is _____________

(a)

2.4 V

(b)

1.2 V

(c)

3.6 V

(d)

4.8 V

A force of 40 N is acting between two charges in air if the space between then is filled with glass ε_r = 8. Then the force between then is __________

(a)

20 N

(b)

10 N

(c)

5 N

(d)

the same and does not change

The concept of 'Field' was introduced by ___________

(a)

Faraday

(b)

Gauss

(c)

Maxwell

(d)

None

The force experienced by a unit charge is called ____________

(a)

Electric potential

(b)

Electric flux

(c)

Electric field

(d)

Static electricity

The expression for electric field in vector form is

(a)

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

(b)

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

(c)

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

(d)

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

Which one of these is a vector quantity?

(a)

Electric charge

(b)

Electric field

(c)

Electric flux

(d)

Electric potential

The electric field created by a _________ is basically a non-uniform electric field.

(a)

Test charge

(b)

Positive charge

(c)

Negative charge

(d)

Point charge

The electric potential V as a function of distance x (metres) is given by V = ( 5x² + 10x -9) volt. The value of electric field at a point x = 1m is __________

(a)

20 Vm^-1

(b)

6 Vm^-1

(c)

11 Vm^-1

(d)

-23 Vm^-1

Two condensers (capacitors) of capacity C₁ and C₂ are connected in parallel. A charge Q given to then is shared. The ratio of the charges Q is _________

(a)

\(\frac { { C }_{ 2 } }{ { C }_{ 1 } } \)

(b)

\(\frac { { C }_{ 1 } }{ { C }_{ 2 } } \)

(c)

C₁.C₂

(d)

\(\frac { 1 }{ { C }_{ 1 }\times { C }_{ 2 } } \)

What will happen if two conducting spheres are separately charged and then brought in contact?

(a)

Total charge on the two spheres is conserved

(b)

The total energy is conserved

(c)

Both charge and energy are conserved

(d)

The final potential is the mean of the original potentials.

A condenser is charged to a potential of 200V and has a charge of 0.1C. The energy stored in it is _____________

(a)

1 J

(b)

2 J

(c)

10 J

(d)

20 J

Increasing the charge on the plates of a capacitor means ___________

(a)

increasing the capacitance

(b)

increasing the potential difference between the plates

(c)

both (a) and (b) above

(d)

none of the above

A positively charged body 'A' has been brought near a brass cylinder 'B' mounted on a glass stand as shown in the figure. The potential of 'B' will be

(a)

zero

(b)

Negative

(c)

positive 

(d)

Infinite

Four plates each of area N and inferplate separation 'd' are placed as shown in figure. The two inner plates are connected to the point 'B' and outer to point 'A'. What is equivalent capacitance?

(a)

\(\frac { { \varepsilon }_{ 0 }A }{ d } \\ \)

(b)

\(\frac { {2 \varepsilon }_{ 0 }A }{ d } \\ \)

(c)

\(\frac { {3 \varepsilon }_{ 0 }A }{ d } \\ \)

(d)

\(\frac { {4 \varepsilon }_{ 0 }A }{ d } \\ \)

Charge per unit volume is called _____________

(a)

Linear charge density (λ)

(b)

Surface charge density (σ)

(c)

Volume charge density (ρ)

(d)

Electric flux