Question 1: Palette 1/33

Objective Physics Vol-2 MCQ

When $10^{14}$ electrons are removed from a neutral metal sphere, the charge on the sphere becomes

A

$16\ \mu\text{C}$

B

$-16\ \mu\text{C}$

C

$32\ \mu\text{C}$

D

$-32\ \mu\text{C}$

Question 2: Palette 2/33

Objective Physics Vol-2 MCQ

A conductor has $14.4 \times 10^{-19}\ \text{C}$ positive charge. The conductor has (charge on electron $= 1.6 \times 10^{-19}\ \text{C}$)

A

9 electrons in excess

B

27 electrons in short

C

27 electrons in excess

D

9 electrons in short

Question 3: Palette 3/33

Objective Physics Vol-2 MCQ

Charge on $\alpha$-particle is

A

$4.8 \times 10^{-19}\text{ C}$

B

$1.6 \times 10^{-19}\text{ C}$

C

$3.2 \times 10^{-19}\text{ C}$

D

$6.4 \times 10^{-19}\text{ C}$

Question 4: Palette 4/33

Objective Physics Vol-2 MCQ

When a glass rod is rubbed with silk, it

A

gains electrons from silk

B

gives electrons to silk

C

gains protons from silk

D

gives protons to silk

Question 5: Palette 5/33

Objective Physics Vol-2 MCQ

When a body is earth connected, electrons from the earth flow into the body. This means the body is

A

uncharged

B

charged positively

C

charged negatively

D

an insulator

Question 6: Palette 6/33

Objective Physics Vol-2 MCQ

There are two charges $+1 \mu\text{C}$ and $+5 \mu\text{C}$. The ratio of the forces acting on them will be

A

$1:5$

B

$1:1$

C

$5:1$

D

$1:25$

Question 7: Palette 7/33

Objective Physics Vol-2 MCQ

$F_g$ and $F_e$ represents gravitational and electrostatic force respectively between electrons situated at a distance $10\text{ cm}$. The ratio of $F_g / F_e$ is of the order of

A

$10^{42}$

B

$10^{-21}$

C

$10^{24}$

D

$10^{-43}$

Question 8: Palette 8/33

Objective Physics Vol-2 MCQ

Two similar small spheres having $+q$ and $-q$ charge are kept at a certain distance. $F$ force acts between them. If in the middle of two spheres, another similar sphere having $+q$ charge is kept, then it will experience a force in magnitude and direction as

A

zero having no direction

B

$8F$ towards $+q$ charge

C

$8F$ towards $-q$ charge

D

$4F$ towards $+q$ charge

Question 9: Palette 9/33

Objective Physics Vol-2 MCQ

The force between two charges $0.06\text{ m}$ apart is $5\text{ N}$. If each charge is moved towards the other by $0.01\text{ m}$, then the force between them will become

A

$7.20\text{ N}$

B

$11.25\text{ N}$

C

$22.50\text{ N}$

D

$45.00\text{ N}$

Question 10: Palette 10/33

Objective Physics Vol-2 MCQ

Two charged spheres separated at a distance $d$ exert a force $F$ on each other. If they are immersed in a liquid of dielectric constant $2$, then what is the force? (if all conditions are same)

A

$F / 2$

B

$F$

C

$2F$

D

$4F$

Question 11: Palette 11/33

Objective Physics Vol-2 MCQ

Electric charges of $1\mu\text{C}$, $-1\mu\text{C}$ and $2\mu\text{C}$ are placed in air at the corners $A$, $B$ and $C$ respectively of an equilateral triangle $ABC$ having length of each side $10\text{ cm}$. The resultant force on the charge at $C$ is

A

$0.9\text{ N}$

B

$1.8\text{ N}$

C

$2.7\text{ N}$

D

$3.6\text{ N}$

Question 12: Palette 12/33

Objective Physics Vol-2 MCQ

Two small conducting spheres of equal radius have charges $+10\mu\text{C}$ and $-20\mu\text{C}$ respectively and placed at a distance $r$ from each other. They experience force $F_1$. If they are brought in contact and separated to the same distance, they experience force $F_2$. The ratio of $F_1$ to $F_2$ is

A

$1:8$

B

$-8:1$

C

$1:2$

D

$-2:1$

Question 13: Palette 13/33

Objective Physics Vol-2 MCQ

Equal charges $Q$ are placed at the four corners $A$, $B$, $C$ and $D$ of a square of length $a$. The magnitude of the force on the charge at $B$ will be

A

$\frac{3Q^2}{4 \pi \varepsilon_0 a^2}$

B

$\frac{Q^2}{4 \pi \varepsilon_0 a^2}$

C

$\left(1 + \frac{2\sqrt{2}}{2}\right)\frac{Q^2}{4 \pi \varepsilon_0 a^2}$

D

$\left(2 + \frac{1}{\sqrt{2}}\right)\frac{Q^2}{4 \pi \varepsilon_0 a^2}$

Question 14: Palette 14/33

Objective Physics Vol-2 MCQ

Two equally charged, identical metal spheres $A$ and $B$ repel each other with a force $F$. The spheres are kept fixed with a distance $r$ between them. A third identical, but uncharged sphere $C$ is brought in contact with $A$ and then placed at the mid-point of the line joining $A$ and $B$. The magnitude of the net electric force on $C$ is

A

$F$

B

$F/4$

C

$F/2$

D

$4F$

Question 15: Palette 15/33

Objective Physics Vol-2 MCQ

Two charges $+4e$ and $+e$ are at a distance $x$ apart. At what distance, a charge $q$ must be placed from charge $+e$, so that it is in equilibrium?

A

$x/2$

B

$2x/3$

C

$x/3$

D

$x/4$

Question 16: Palette 16/33

Objective Physics Vol-2 MCQ

A charge $Q$ is placed at each of the two opposite corners of a square. A charge $q$ is placed at each of the other two corners. If the resultant force on $Q$ is zero, then

A

$Q = \sqrt{2}q$

B

$Q = -\sqrt{2}q$

C

$Q = 2\sqrt{2}q$

D

$Q = -2\sqrt{2}q$

Question 17: Palette 17/33

Objective Physics Vol-2 MCQ

A charge $q$ is lying at mid-point of the line joining the two similar charges $Q$. The system will be in equilibrium if the value of $q$ is

A

$Q / 2$

B

$-Q / 2$

C

$Q / 4$

D

$-Q / 4$

Question 18: Palette 18/33

Objective Physics Vol-2 MCQ

Two point charges $+2\text{ C}$ and $+6\text{ C}$ repel each other with a force of $12\text{ N}$. If a charge of $-4\text{ C}$ is given to each of these charges, the force now is

A

$4\text{ N}$ (repulsive)

B

$4\text{ N}$ (attractive)

C

$12\text{ N}$ (attractive)

D

$8\text{ N}$ (repulsive)

Question 19: Palette 19/33

Objective Physics Vol-2 MCQ

A charge $q_1$ exerts some force on a second charge $q_2$. If a third charge $q_3$ is brought near $q_2$, the force exerted by $q_1$ on $q_2$

A

decreases

B

increases

C

remains the same

D

increases if $q_3$ is of same sign as $q_1$ and decreases if $q_3$ is of opposite sign as $q_1$

Question 20: Palette 20/33

Objective Physics Vol-2 MCQ

Three equal charges are placed on the three corners of a square. If the force between $q_1$ and $q_2$ is $F_{12}$ and that between $q_1$ and $q_3$ is $F_{13}$, then the ratio of magnitudes $(F_{12} / F_{13})$ is

A

$1 / 2$

B

$2$

C

$1 / \sqrt{2}$

D

$\sqrt{2}$

Question 21: Palette 21/33

Objective Physics Vol-2 MCQ

The centres of two identical small conducting spheres are $1\text{ m}$ apart. They carry charges of opposite kind and attract each other with a force $F$. When they are connected by a conducting thin wire they repel each other with a force $F/3$. What is the ratio of magnitude of charges carried by the spheres initially?

A

$1 : 1$

B

$2 : 1$

C

$3 : 1$

D

$4 : 1$

Question 22: Palette 22/33

Objective Physics Vol-2 MCQ

A metallic sphere having no net charge is placed near a finite metal plate carrying a positive charge. The electric force on the sphere will be

A

towards the plate

B

away from the plate

C

parallel to the plate

D

zero

Question 23: Palette 23/33

Objective Physics Vol-2 MCQ

Figure shows the electric lines of force emerging from a charged body. If the electric field at $A$ and $B$ are $E_A$ and $E_B$ respectively and if the distance between $A$ and $B$ is $r$, then

A

$E_A > E_B$

B

$E_A < E_B$

C

$E_A = \frac{E_B}{r}$

D

$E_A = \frac{E_B}{r^2}$

Question 24: Palette 24/33

Objective Physics Vol-2 MCQ

$ABC$ is an equilateral triangle. Charges $+q$ are placed at each corner. The electric intensity at $O$ will be

A

$\frac{1}{4\pi\varepsilon_0} \frac{q}{r^2}$

B

$\frac{1}{4\pi\varepsilon_0} \frac{q}{r}$

C

zero

D

$\frac{1}{4\pi\varepsilon_0} \frac{3q}{r^2}$

Question 25: Palette 25/33

Objective Physics Vol-2 MCQ

The insulation property of air breaks down at $E = 3 \times 10^6$ V/m. The maximum charge that can be given to a sphere of diameter $5$ m is approximately (in coulombs)

A

$2 \times 10^{-2}$

B

$2 \times 10^{-3}$

C

$2 \times 10^{-4}$

D

$2 \times 10^{-5}$

Question 26: Palette 26/33

Objective Physics Vol-2 MCQ

The distance between the two charges $25$ microcoulombs and $36$ microcoulombs is $11$ cm. At what point on the line joining the two, the intensity will be zero?

A

At a distance of $5$ cm from $25$ microcoulombs

B

At a distance of $5$ cm from $36$ microcoulombs

C

At a distance of $4$ cm from $25$ microcoulombs

D

At a distance of $4$ cm from $36$ microcoulombs

Question 27: Palette 27/33

Objective Physics Vol-2 MCQ

The electric field near a conducting surface having a uniform surface charge density $\sigma$ is given by

A

$\frac{\sigma}{\varepsilon_0}$ and is parallel to the surface

B

$\frac{2\sigma}{\varepsilon_0}$ and is parallel to the surface

C

$\frac{\sigma}{\varepsilon_0}$ and is normal to the surface

D

$\frac{\sigma}{2\varepsilon_0}$ and is normal to the surface

Question 28: Palette 28/33

Objective Physics Vol-2 MCQ

The unit of electric field is not equivalent to

A

N/C

B

J/C

C

V/m

D

J/C-m

Question 29: Palette 29/33

Objective Physics Vol-2 MCQ

A metallic solid sphere is placed in a uniform electric field. The lines of force follow the path(s) shown in figure as

A

1

B

2

C

3

D

4

Question 30: Palette 30/33

Objective Physics Vol-2 MCQ

The figure shows some of the electric field lines corresponding to an electric field. The figure suggests

A

$E_A > E_B > E_C$

B

$E_A = E_B = E_C$

C

$E_A = E_C > E_B$

D

$E_A = E_C < E_B$

Question 31: Palette 31/33

Objective Physics Vol-2 MCQ

Two spheres of radius $a$ and $b$ respectively are charged and joined by a wire. The ratio of electric field of the spheres is

A

$a/b$

B

$b/a$

C

$a^2/b^2$

D

$b^2/a^2$

Question 32: Palette 32/33

Objective Physics Vol-2 MCQ

A cube of side $b$ has a charge $q$ at each of its vertices. The electric field due to this charge distribution at the centre of this cube will be $\frac{1}{4\pi\varepsilon_0}$ times

A

$q/b^2$

B

$q/2b^2$

C

$32q/b^2$

D

zero

Question 33: Palette 33/33

Objective Physics Vol-2 MCQ

Figures below show regular hexagons, with charges at the vertices. In which of the following cases the electric field at the centre is not zero?

A

1

B

2

C

3

D

4