2000
Q1
Allen
6. ELECTRICAL POTENTIAL ENERGY
MCQ
A 5 C charge experiences a force of 2000 N when moved between two points along the field separated by a distance of 2 cm in a uniform electric field. The potential difference between the two points is:-
A.
8 volts
B.
80 volts
C.
800 volts
D.
8000 volts
1980
Q2
Allen
9. PYQ
MCQ
Twenty seven drops of same size are charged at 220 V each. They combine to form a bigger drop. Calculate the potential of the bigger drop.
A.
660 V
B.
1320 V
C.
1520 V
D.
1980 V
Q3
Allen
1. ELECTRIC CHARGE & METHODS OF CHARGING
MCQ
Which of the following charges cannot be present on an oil drop in Millikan's experiment:-
A.
$4.0 \times 10^{-19}$ C
B.
$6.0 \times 10^{-19}$ C
C.
$10.0 \times 10^{-19}$ C
D.
all of them
Q4
Allen
1. ELECTRIC CHARGE & METHODS OF CHARGING
MCQ
In nature, the electric charge of any system is always equal to :
A.
half integral multiple of the least amount of charge
B.
zero
C.
square of the least amount of charge
D.
integral multiple of the least amount of charge
Q5
Allen
1. ELECTRIC CHARGE & METHODS OF CHARGING
MCQ
Consider a neutral conducting sphere. A positive point charge is placed outside the sphere. The net charge on the sphere is then:
A.
negative and distributed uniformly over its surface.
B.
negative and appears only at the point on the sphere closest to the point charge
C.
negative and distributed non-uniformly over its entire surface of the sphere
D.
zero
Q6
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
Force between two identical spheres charged with same charge is F. If 50% charge of one sphere is transferred to the other sphere then the new force will be :-
A.
$\frac{3}{4}\mathrm{F}$
B.
$\frac{3}{8}\mathrm{F}$
C.
$\frac{3}{2}\mathrm{F}$
D.
none of these
Q7
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
Two point charges placed at a distance 'r' in air exert a force 'F'. The distance at which they exert same force when placed in a certain medium (dielectric constant K) is:-
A.
rK
B.
r/K
C.
$\mathrm{r} / \sqrt{\mathrm{K}}$
D.
$\mathrm{r}\sqrt{\mathrm{K}}$
Q8
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
Two charges are placed as shown in figure. Where should a third charge be placed so that it remains at rest?
A.
30 cm from 9e
B.
40 cm from 16e
C.
40 cm from 9e
D.
1) or 2)
Q9
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
Two point charges +9q and +q are kept 16 cm apart. Where should a third charge Q be placed between them so that the system remains in equilibrium?
A.
24 cm from +9q
B.
12 cm from +9q
C.
24 cm from +q
D.
12 cm from +q
Q10
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
Two balls carrying charges +7 Ī¼C and -5 Ī¼C attract each other with a force F. If a charge -2 Ī¼C is added to both, the force between them will be :-
A.
F
B.
$\frac{F}{2}$
C.
2F
D.
zero
Q11
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
Two equal and like charges when placed 5 cm apart experience a repulsive force of 0.144 newtons. The magnitude of the charge in micro-coulomb will be
A.
0.2
B.
2
C.
20
D.
12
Q12
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
Two point charges of + 2 Ī¼C and + 6 Ī¼C repel each other with a force of 12 N. If each is given an additional charge of - 4 Ī¼C, then force will become:-
A.
4 N (attractive)
B.
60 N (attractive)
C.
4 N (repulsive)
D.
12 N (attractive)
Q13
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
What equal charges should to be placed on earth and moon to neutralize their gravitational attraction? (mass of earth = $10^{25}$ kg, mass of moon = $10^{23}$ kg)
A.
$8.6 \times 10^{13}$ C
B.
$6.8 \times 10^{26}$ C
C.
$8.6 \times 10^{3}$ C
D.
$9 \times 10^{6}$ C
Q14
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
A point charge $q_{1}$ exerts a force F upon another point charge $q_{2}$ . If a third charge $q_{3}$ be placed quite close to the charge $q_{2}$ then the force that charge $q_{1}$ exerts on the charge $q_{2}$ will be :-
A.
F
B.
> F
C.
< F
D.
zero
Q15
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
A charge $Q$ is divided in two parts $Q_{1}$ and $Q_{2}$ and these charges are placed at a distance $R$ . There will be maximum repulsion between them when:
A.
$Q_{1} = Q - q; Q_{2} = q$
B.
$Q_{1} = \frac{2Q}{3}, Q_{2} = \frac{Q}{3}$
C.
$Q_{1} = \frac{3Q}{4}, Q_{2} = \frac{Q}{4}$
D.
$Q_{1} = Q_{2} = \frac{Q}{2}$
Q16
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
The force of repulsion between two point charges is F, when these are 1 m apart. Now the point charges are replaced by conducting spheres of radii 5 cm having the charge same as that of point charges. The distance between their centres is 1 m, then the force of repulsion will :-
A.
increase
B.
decrease
C.
remain same
D.
become $\frac{10\mathrm{F}}{9}$
Q17
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
Two charges 4q and q are placed at a distance $\ell$ apart. A third charged particle Q is placed at the middle of them. If resultant force on q is zero then the value of Q is:-
A.
q
B.
- q
C.
2q
D.
- 2q
Q18
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
Two similar spheres having +q and -q charges are kept at a certain separation. F force acts between them. If another similar sphere having +q charge is kept in the middle of them, it experiences 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
Q19
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
Four charges are placed at the circumference of the dial of a clock as shown in figure. If the clock has only hour hand, then the resultant force on a positive charge $q_{0}$ placed at the centre, points in the direction which shows the time as :-
A.
1:30
B.
7:30
C.
4:30
D.
10:30
Q20
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
Two small spheres each having a charge +Q are suspended by insulating threads of length L from a hook. This arrangement is taken to a space where there is no gravitational effect, then the angle between the two threads and the tension in each will be :-
A.
$180^{\circ}, \frac{1}{4\pi\varepsilon_{0}} \frac{Q^{2}}{(2L)^{2}}$
B.
$90^{\circ}, \frac{1}{4\pi\varepsilon_{0}} \frac{Q^{2}}{L^{2}}$
C.
$180^{\circ}, \frac{1}{4\pi\varepsilon_{0}} \frac{Q^{2}}{2L^{2}}$
D.
$180^{\circ}, \frac{1}{4\pi\varepsilon_{0}} \frac{Q^{2}}{L^{2}}$
Q21
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
Identify the wrong statement in the following :- Coulomb's law correctly describes the electric force that.
A.
binds the electrons of an atom to its nucleus
B.
binds the protons and neutrons in the nucleus of an atom
C.
binds the atoms together to form molecules
D.
binds the atoms and molecules together to form solids
Q22
Allen
2. COULOMB'S LAW AND EQUILIBRIUM OF CHARGE SYSTEM
MCQ
In the fig. force on charge at A in the direction normal to BC will be :-
A.
$-\frac{\mathrm{kq}}{\mathrm{a}^2}$
B.
$-\frac{\mathrm{kq}^2}{2\mathrm{a}^2}$
C.
$\frac{\mathrm{kq}^2}{2\mathrm{a}^2}$
D.
$\frac{\sqrt{3}\mathrm{kq}^2}{\mathrm{a}^2}$
Q23
Allen
3. ELECTRIC FIELD INTENSITY
MCQ
Two charges 9e and 3e are placed at a separation r. The distance of the point where the electric field intensity will be zero, is:-
A.
$\frac{r}{(1 + \sqrt{3})}$ from 9e charge
B.
$\frac{\sqrt{3}r}{\sqrt{3} + 1}$ from 9e charge
C.
$\frac{r}{(1 - \sqrt{3})}$ from 3e charge
D.
$\frac{\sqrt{3}r}{1 + \sqrt{3}}$ from 3e charge
Q24
Allen
3. ELECTRIC FIELD INTENSITY
MCQ
A ring of radius R is charged uniformly with a charge + Q. The electric field at a point on its axis at a distance r from any point on the ring will be :-
A.
$\frac{\mathrm{KQ}}{(\mathrm{r}^2 - \mathrm{R}^2)}$
B.
$\frac{\mathrm{KQ}}{\mathrm{r}^2}$
C.
$\frac{\mathrm{KQ}}{\mathrm{r}^3} (\mathrm{r}^2 - \mathrm{R}^2)^{1/2}$
D.
$\frac{\mathrm{KQr}}{\mathrm{R}^3}\mathrm{a}$
Q25
Allen
3. ELECTRIC FIELD INTENSITY
MCQ
Two positive charges of 1 $\mu$ C and 2 $\mu$ C are placed 1 metre apart. The value of electric field in N/C at the mid point of the two charges will be:-
A.
$10.8 \times 10^{4}$
B.
$3.6 \times 10^{4}$
C.
$1.8 \times 10^{4}$
D.
$5.4 \times 10^{4}$