Total Questions:50 Total Time: 75 Min
Remaining:
Question:An isolated solid metallic sphere is given \( + Q\) charge. The charge will be distributed on the sphere
Uniformly but only on surface
Only on surface but non-uniformly
Uniformly inside the volume
Non-uniformly inside the volume
Question:Two small spheres each having the charge \( + Q\) are suspended by insulating threads of length \(L\) from a hook. This arrangement is taken in space where there is no gravitational effect, then the angle between the two suspensions and the tension in each will be
\({180^o},\,\frac{1}{{4\pi {\varepsilon_0}}}\frac{{{Q^2}}}{{{{(2L)}^2}}}\)
\({90^o},\,\frac{1}{{4\pi {\varepsilon _0}}}\frac{{{Q^2}}}{{{L^2}}}\)
\({180^o},\,\frac{1}{{4\pi {\varepsilon _0}}}\frac{{{Q^2}}}{{2{L^2}}}\)
\({180^o},\,\frac{1}{{4\pi {\varepsilon _0}}}\frac{{{Q^2}}}{{{L^2}}}\)
Question:Two similar spheres having \( + \,q\) and \( - \,q\) charge are kept at a certain distance. \(F\) force acts between the two. If in the middle of two spheres, another similar sphere having \( + \,q\) charge is kept, then it experience a force in magnitude and direction as
Zero having no direction
\(8F\) towards \( + \,q\) charge
\(8F\) towards \( - \,q\) charge
\(4F\) towards \( + \,q\) charge
Question:A charge \(Q\) is divided into two parts of \(q\) and \(Q - q\) . If the coulomb repulsion between them when they are separated is to be maximum, the ratio of \(\frac{Q}{q}\) should be
2
\(1/2\)
4
\(1/4\)
Question:Two copper balls, each weighing 10g are kept in air 10 cm apart. If one electron from every \({10^6}\) atoms is transferred from one ball to the other, the coulomb force between them is (atomic weight of copper is 63.5)
\(2.0 \times {10^{10}}\)N
\(2.0 \times {10^4}\)N
\(2.0 \times {10^8}\)N
\(2.0 \times {10^6}\)N
Question:Three charges each of magnitude q are placed at the corners of an equilateral triangle, the electrostatic force on the charge placed at the center is (each side of triangle is L)
Zero
\(\frac{1}{{4\pi {\varepsilon _0}}}\frac{{{q^2}}}{{{L^2}}}\)
\(\frac{1}{{4\pi {\varepsilon _0}}}\frac{{3{q^2}}}{{{L^2}}}\)
\(\frac{1}{{12\pi {\varepsilon _0}}}\frac{{{q^2}}}{{{L^2}}}\)
Question:The ratio of electrostatic and gravitational forces acting between electron and proton separated by a distance \(5 \times {10^{ - 11}}m,\) will be (Charge on electron = 1.6 x 10\(^{ - 19}\) C, mass of electron = 9.1 x 10\(^{ - 31}\) kg, mass of proton = \(1.6 \times {10^{ - 27}}kg,\) \(\,G = 6.7 \times {10^{ - 11}}\,N{m^2}/k{g^2})\)
2.36 x 10\(^{39}\)
2.36 x 10\(^{40}\)
2.34 x 10\(^{41}\)
2.34 x 10\(^{42}\)
Question:If a unit positive charge is taken from one point to another over an equipotential surface, then
Work is done on the charge
Work is done by the charge
Work done is constant
No work is done
Question:The intensity of electric field required to balance a proton of mass \(1.7 \times {10^{ - 27}}kg\) and charge\(1.6 \times {10^{ - 19}}C\) is nearly
\(1 \times {10^{ - 7}}\;V/m\)
\(1 \times {10^{ - 5}}\;V/m\)
\(1 \times {10^7}\;V/m\)
\(1 \times {10^5}\;V/m\)
Question:At a certain distance from a point charge the electric field is \(500\,V/m\) and the potential is \(3000\,V\). What is this distance
\(6\,m\)
\(12\,m\)
\(36\,m\)
\(144\,m\)
Question:An alpha particle is accelerated through a potential difference of \({10^6}\,volt\). Its kinetic energy will be
\(1\,MeV\)
\(2\,MeV\)
\(4\,MeV\)
\(8\,MeV\)
Question:What is the potential energy of the equal positive point charges of \(1\mu C\) each held 1 m apart in air
\(9 \times {10^{ - 3}}J\)
\(9 \times {10^{ - 3}}eV\)
\(2eV/m\)
Question:There is a solid sphere of radius 'R' having uniformly distributed charge. What is the relation between electric field 'E' (inside the sphere) and radius of sphere 'R' is
\(E \propto {R^{ - 2}}\)
\(E \propto {R^{ - 1}}\)
\(E \propto \frac{1}{{{R^3}}}\)
\(E \propto {R^2}\)
Question:A particle of mass 'm' and charge 'q' is accelerated through a potential difference of V volt, its energy will be
\(qV\)
\(mqV\)
\(\left( {\frac{q}{m}} \right)V\)
\(\frac{q}{{mV}}\)
Question:Two point charges \( + 9e\) and \( + e\) are at 16 cm away from each other. Where should another charge q be placed between them so that the system remains in equilibrium
24 cm from \( + 9e\)
12 cm from \( + 9e\)
24 cm from \( + e\)
12 cm from \( + e\)
Question:A pellet carrying charge of 0.5 coulombs is accelerated through a potential of 2,000 volts. It attains a kinetic energy equal to
1000 ergs
1000 joules
1000 kWh
500 ergs
Question:Electric potential of earth is taken to be zero because earth is a good
Insulator
Conductor
Semiconductor
Dielectric
Question:In a certain charge distribution, all points having zero potential can be joined by a circle S. Points inside S have positive potential and points outside S have negative potential. A positive charge, which is free to move, is placed inside S
It will remain in equilibrium
It can move inside S, but it cannot cross S
It must cross S at some time
It may move, but will ultimately return to its starting point
Question:The electric potential at a point on the axis of an electric dipole depends on the distance \(r\) of the point from the dipole as
\( \propto \frac{1}{r}\)
\( \propto \frac{1}{{{r^2}}}\)
\( \propto r\)
\( \propto \frac{1}{{{r^3}}}\)
Question:An electric dipole is placed in an electric field generated by a point charge
The net electric force on the dipole must be zero
The net electric force on the dipole may be zero
The torque on the dipole due to the field must be zero
The torque on the dipole due to the field may be zero
Question:Two electric dipoles of moment P and 64 P are placed in opposite direction on a line at a distance of 25 cm. The electric field will be zero at point between the dipoles whose distance from the dipole of moment P is
5 cm
\(\frac{{25}}{9}\)cm
10 cm
\(\frac{4}{{13}}\) cm
Question:The S.I. unit of electric flux is
Weber
Newton per coulomb
Volt x metre
Joule per coulomb
Question:The insulated spheres of radii \({R_1}\) and \({R_2}\) having charges \({Q_1}\)and \({Q_2}\) respectively are connected to each other. There is
No change in the energy of the system
An increase in the energy of the system
Always a decrease in the energy of the system
A decrease in the energy of the system unless \({Q_1}{R_2} = {Q_2}{R_1}\)
Question:1000 small water drops each of radius r and charge \(q\)coalesce together to form one spherical drop. The potential of the big drop is larger than that of the smaller drop by a factor of
1000
100
10
1
Question:The distance between the plates of a parallel plate condenser is \(4mm\) and potential difference is\(60\;volts\). If the distance between the plates is increased to\(12mm\), then
The potential difference of the condenser will become \(180\;volts\)
The P.D. will become \(20\;volts\)
The P.D. will remain unchanged
The charge on condenser will reduce to one third
Question:Two metallic charged spheres whose radii are 20\(cm\) and 10\(cm\) respectively, have each 150\(micro - coulomb\) positive charge. The common potential after they are connected by a conducting wire is
\(9 \times {10^6}\;volts\)
\(4.5 \times {10^6}\;volts\)
\(1.8 \times {10^7}\;volts\)
\(13.5 \times {10^6}\;volts\)
Question:An air capacitor is connected to a battery. The effect of filling the space between the plates with a dielectric is to increase
The charge and the potential difference
The potential difference and the electric field
The electric field and the capacitance
The charge and the capacitance
Question:A parallel plate capacitor has a capacity \(C\). The separation between the plates is doubled and a dielectric medium is introduced between the plates. If the capacity now becomes\(2C\), the dielectric constant of the medium is
8
Question:The force between the plates of a parallel plate capacitor of capacitance\(C\) and distance of separation of the plates \(d\) with a potential difference \(V\) between the plates, is
\(\frac{{C{V^2}}}{{2d}}\)
\(\frac{{{C^2}{V^2}}}{{2{d^2}}}\)
\(\frac{{{C^2}{V^2}}}{{{d^2}}}\)
\(\frac{{{V^2}d}}{C}\)
Question:Two metal spheres of capacitance \({C_1}\) and \({C_2}\) carry some charges. They are put in contact and then separated. The final charges \({Q_1}\) and \({Q_2}\) on them will satisfy
\(\frac{{{Q_1}}}{{{Q_2}}} < \frac{{{C_1}}}{{{C_2}}}\)
\(\frac{{{Q_1}}}{{{Q_2}}} = \frac{{{C_1}}}{{{C_2}}}\)
\(\frac{{{Q_1}}}{{{Q_2}}} > \frac{{{C_1}}}{{{C_2}}}\)
\(\frac{{{Q_1}}}{{{Q_2}}} < \frac{{{C_2}}}{{{C_1}}}\)
Question:When a dielectric material is introduced between the plates of a charged condenser then electric field between the plates
Decreases
Increases
Remain constant
First
Question:A parallel plate capacitor has a plate separation of 0.01 mm and use a dielectric (whose dielectric strength is 19 KV/mm) as an insulator. The maximum potential difference that can be applied to the terminals of the capacitor is
190 V
290 V
95 V
350 V
Question:The capacity of the conductor does not depend upon
Charge
Voltage
Nature of the material
All of these
Question:A solid conducting sphere of radius \({R_1}\) is surrounded by another concentric hollow conducting sphere of radius \({R_2}\). The capacitance of this assembly is proportional to
\(\frac{{{R_2} - {R_1}}}{{{R_1}{R_2}}}\)
\(\frac{{{R_2} + {R_1}}}{{{R_1}{R_2}}}\)
\(\frac{{{R_1}{R_2}}}{{{R_1} + {R_2}}}\)
\(\frac{{{R_1}{R_2}}}{{{R_2} - {R_1}}}\)
Question:A conducting sphere of radius 10cm is charged \(10\mu \,C\). Another uncharged sphere of radius 20 cm is allowed to touch it for some time. After that if the sphere are separated, then surface density of charges, on the spheres will be in the ratio of
1:04
1:03
2:01
1:01
Question:64 small drops of mercury, each of radius r and charge q coalesce to form a big drop. The ratio of the surface density of charge of each small drop with that of the big drop is
0.086
64:01:00
4:01
Question:A capacitor is charged to 200 volt it has 0.1 coulomb charge. When it is discharged, energy will be
1 J
4 J
10 J
20 J
Question:If eight identical drops are joined to form a bigger drop, the potential on bigger as compared to that on smaller drop will be
Double
Four times
Eight times
One time
Question:The potentials of the two plates of capacitor are +10V and -10 V. The charge on one of the plates is 40 C. The capacitance of the capacitor is
2 F
4 F
0.5 F
0.25 F
Question:The potential to which a conductor is raised, depends on
The amount of charge
Geometry and size of the conductor
Both 1 and 2
Only on
Question:Two capacitors connected in parallel having the capacities \({C_1}\)and \({C_2}\) are given \('q'\) charge, which is distributed among them. The ratio of the charge on \({C_1}\)and \({C_2}\) will be
\(\frac{{{C_1}}}{{{C_2}}}\)
\(\frac{{{C_2}}}{{{C_1}}}\)
\({C_1}{C_2}\)
\(\frac{1}{{{C_1}{C_2}}}\)
Question:Two capacitors of capacities \({C_1}\) and \({C_2}\) are charged to voltages \({V_1}\) and \({V_2}\) respectively. There will be no exchange of energy in connecting them in parallel, if
\({C_1} = {C_2}\)
\({C_1}{V_1} = {C_2}{V_2}\)
\({V_1} = {V_2}\)
\(\frac{{{C_1}}}{{{V_1}}} = \frac{{{C_2}}}{{{V_2}}}\)
Question:Two capacitors of 3pF and 6pF are connected in series and a potential difference of 5000\(V\) is applied across the combination. They are then disconnected and reconnected in parallel. The potential between the plates is
2250\(V\)
2222\(V\)
\(2.25 \times {10^6}V\)
\(1.1 \times {10^6}V\)
Question:Two identical parallel plate capacitors are connected in series to a battery of 100\(V\). A dielectric slab of dielectric constant 4.0 is inserted between the plates of second capacitor. The potential difference across the capacitors will now be respectively
50 V, 50 V
80 V, 20 V
20 V, 80 V
75 V, 25 V
Question:Three capacitors of capacitance \(3\mu \,F,\,10\mu \,F\,\) and \(15\mu \,F\,\) are connected in series to a voltage source of 100V. The charge on \(15\mu \,F\,\)is
\(50\,\mu \,C\)
\(100\,\mu \,C\)
\(200\,\mu \,C\)
\(280\,\mu \,C\)
Question:A 20F capacitor is charged to 5V and isolated. It is then connected in parallel with an uncharged 30F capacitor. The decrease in the energy of the system will be
25 J
200 J
125 J
150 J
Question:A 10 \(\mu \)F capacitor is charged to a potential difference of 1000 V. The terminals of the charged capacitor are disconnected from the power supply and connected to the terminals of an uncharged 6\(\mu \)F capacitor. What is the final potential difference across each capacitor
167 V
100 V
625 V
250 V
Question:In the given circuit if point C is connected to the earth and a potential of \( + \,2000\,V\) is given to the point A, the potential at B is
\(1500\,V\)
\(1000\;V\)
\(500\;V\)
\(400\;V\)
Question:Figure shows two capacitors connected in series and joined to a battery. The graph in figure shows the variation in potential as one moves from left to right on the branch containing the capacitors, if
\({C_1} > {C_2}\)
\({C_1} < {C_2}\)
The information is not sufficient to decide the relation between \({C_1}\)and \({C_2}\)
Question:During charging a capacitor variation of potential V of the capacitor with time t is shown as