Total Questions:50 Total Time: 75 Min
Remaining:
Question:A body can be negatively charged by
Giving excess of electrons to it
Removing some electrons from it
Giving some protons to it
Removing some neutrons from it
Question:Force of attraction between two point charges \(Q\) and – Q separated by \(d\,metre\) is \({F_e}\) . When these charges are placed on two identical spheres of radius \(R = 0.3\,d\) whose centres are \(d\,metre\) apart, the force of attraction between them is
Greater than \({F_e}\)
Equal to \({F_e}\)
Less than \({F_e}\)
Question:Charge on \(\alpha \) -particle is
\(4.8 \times {10^{ - 19}}C\)
\(1.6 \times {10^{ - 19}}C\)
\(3.2 \times {10^{ - 19}}C\)
\(6.4 \times {10^{ - 19}}C\)
Question:Equal charges \(q\) are placed at the four corners \(A,\,B,\,C,\,D\) of a square of length \(a\). The magnitude of the force on the charge at B will be
\(\frac{{3{q^2}}}{{4\pi {\varepsilon _0}{a^2}}}\)
\(\frac{{4{q^2}}}{{4\pi {\varepsilon _0}{a^2}}}\)
\(\left( {\frac{{1 + 2\sqrt 2 }}{2}} \right)\frac{{{q^2}}}{{4\pi {\varepsilon _0}{a^2}}}\)
\(\left( {2 + \frac{1}{{\sqrt 2 }}} \right)\frac{{{q^2}}}{{4\pi {\varepsilon _0}{a^2}}}\)
Question:The electric charge in uniform motion produces
An electric field only
A magnetic field only
Both electric and magnetic field
Neither electric nor magnetic field
Question:The distance between the two charges \(25\mu C\) and \(36\mu C\) is \(11cm\) At what point on the line joining the two, the intensity will be zero
At a distance of \(5\,cm\)from \(25\mu C\)
At a distance of \(5\,cm\)from \(36\mu C\)
At a distance of \(10\,cm\)from \(25\mu C\)
At a distance of \(11\,cm\)from \(36\mu C\)
Question:Two spheres \(A\)and \(B\) of radius \(4cm\) and \(6cm\) are given charges of \(80\mu c\) and \(40\mu c\)respectively. If they are connected by a fine wire, the amount of charge flowing from one to the other is
\(20\mu C\)from \(A\)to \(B\)
\(16\mu C\) from \(A\)to \(B\)
\(32\mu C\)from \(B\) to \(A\)
\(32\mu C\) from \(A\)to \(B\)
Question:Four equal charges \(Q\) are placed at the four corners of a square of each side is \('a'\). Work done in removing a charge -Q from its centre to infinity is
0
\(\frac{{\sqrt 2 {Q^2}}}{{4\pi {\varepsilon _0}a}}\)
\(\frac{{\sqrt 2 {Q^2}}}{{\pi {\varepsilon _0}a}}\)
\(\frac{{{Q^2}}}{{2\pi {\varepsilon _0}a}}\)
Question:A particle \(A\) has charge \( + q\) and a particle \(B\) has charge \( + \,4q\) with each of them having the same mass \(m\). When allowed to fall from rest through the same electric potential difference, the ratio of their speed \(\frac{{{v_A}}}{{{v_B}}}\) will become
\(2:1\)
\(1:2\)
\(1:4\)
\(4:1\)
Question:Two insulated charged conducting spheres of radii \(20\,cm\) and \(15\,cm\)respectively and having an equal charge of \(10\,C\) are connected by a copper wire and then they are separated. Then
Both the spheres will have the same charge of \(10\,C\)
Surface charge density on the \(20\,cm\) sphere will be greater than that on the \(15\,cm\) sphere
Surface charge density on the \(15\,cm\)sphere will be greater than that on the \(20\,cm\) sphere
Surface charge density on the two spheres will be equal
Question:Equal charges \(q\) are placed at the vertices \(A\) and \(B\) of an equilateral triangle \(ABC\) of side \(a\). The magnitude of electric field at the point \(C\) is
\(\frac{q}{{4\pi {\varepsilon _0}{a^2}}}\)
\(\frac{{\sqrt 2 \,q}}{{4\pi {\varepsilon _0}{a^2}}}\)
\(\frac{{\sqrt 3 \,q}}{{4\pi {\varepsilon _0}{a^2}}}\)
\(\frac{q}{{2\pi {\varepsilon _0}{a^2}}}\)
Question:A sphere of radius \(1\,cm\) has potential of \(8000\,V\), then energy density near its surface will be
\(64 \times {10^5}J/{m^3}\)
\(8 \times {10^3}J/{m^3}\)
\(32\,J/{m^3}\)
\(2.83\,J/{m^3}\)
Question:Point charges \( + 4q,\, - q\) and \( + 4q\) are kept on the \(x - \)axis at points \(x = 0,\,x = a\) and \(x = 2a\) respectively, then
Only \(q\) is in stable equilibrium
None of the charges are in equilibrium
All the charges are in unstable equilibrium
All the charges are in stable equilibrium
Question:Two charges of \(4\mu C\) each are placed at the corners A and B of an equilateral triangle of side length 0.2 m in air. The electric potential at C is \(\left[ {\frac{1}{{4\pi {\varepsilon _0}}} = 9 \times {{10}^9}\frac{{N{\rm{ - }}{m^2}}}{{{C^2}}}} \right]\)
\(9 \times {10^4}\)V
\(18 \times {10^4}\)V
\(36 \times {10^4}\)V
\(36 \times {10^{ - 4}}\)V
Question:Electric field strength due to a point charge of \(5\mu C\) at a distance of 80 cm from the charge is
\(8 \times {10^4}\)N/C
\(7 \times {10^4}\)N/C
\(5 \times {10^4}\)N/C
\(4 \times {10^4}\)N/C
Question:The dimension of (1/2) \({\varepsilon _0}{E^2}({\varepsilon _0}\): permittivity of free space; \(E\): electric field) is
\(ML{T^{^{ - 1}}}\)
\(M{L^2}{T^{ - 2}}\)
\(M{L^{ - 1}}{T^{ - 2}}\)
\(M{L^2}{T^{ - 1}}\)
Question:A cube of a metal is given a positive charge Q. For the above system, which of the following statements is true
Electric potential at the surface of the cube is zero
Electric potential within the cube is zero
Electric field is normal to the surface of the cube
Electric field varies within the cube
Question:The work done in bringing a 20 coulomb charge from point A to point B for distance 0.2m is 2J. The potential difference between the two points will be (in volt)
0.2
8
0.1
0.4
Question:A hollow sphere of charge does not produce an electric field at any
Point beyond 2 metres
Point beyond 10 metres
Interior point
Outer point
Question:A conducting sphere of radius \(R = 20\)cm is given a charge \(Q = 16\mu C\). What is \(\overrightarrow E \) at centre
\(3.6 \times {10^6}N/C\)
\(1.8 \times {10^6}N/C\)
Zero
\(0.9 \times {10^6}N/C\)
Question:A thin spherical conducting shell of radius \(R\) has a charge q. Another charge Q is placed at the centre of the shell. The electrostatic potential at a point p a distance \(\frac{R}{2}\) from the centre of the shell is
\(\frac{{(q + Q)}}{{4\pi {\varepsilon _0}}}\frac{2}{R}\)
\(\frac{{2Q}}{{4\pi
{\varepsilon _0}R}}\)
\(\frac{{2Q}}{{4\pi {\varepsilon _0}R}} - \frac{{2q}}{{4\pi {\varepsilon _0}R}}\)
Question:When a negative charge is taken at a height from earth's surface, then its potential energy
Decreases
Increases
Remains unchanged
Will become infinity
Question:When a charge of 3 coulombs is placed in a uniform electric field, it experiences a force of 3000 Newton. Within this field, potential difference between two points separated by a distance of 1 cm is
10 volts
90 volts
1000 volts
3000 volts
Question:The potential at a distance R/2 from the centre of a conducting sphere of radius R will be
\(\frac{Q}{{8\pi {\varepsilon _0}R}}\)
\(\frac{Q}{{4\pi {\varepsilon _0}R}}\)
\(\frac{Q}{{2\pi {\varepsilon _0}R}}\)
Question:Four charges \( + Q,\, - Q,\, + Q,\, - Q\) are placed at the corners of a square taken in order. At the centre of the square
\(E = 0,\,V = 0\)
\(E = 0,\,V \ne 0\)
\(E \ne 0,\,V = 0\)
Question:At a point 20 cm from the centre of a uniformly charged dielectric sphere of radius 10 cm, the electric field is 100 V/m. The electric field at 3 cm from the centre of the sphere will be
150 V/m
125 V/m
120 V/m
Question:Charges 4Q, q and Q and placed along x-axis at positions \(x = 0,x = l/2\) and \(x = l\), respectively. Find the value of q so that force on charge Q is zero
Q
Q / 2
Question:An electric dipole is placed along the \(x - \)axis at the origin \(O\). A point \(P\) is at a distance of \(20\,cm\) from this origin such that \(OP\) makes an angle \(\frac{\pi }{3}\) with the x-axis. If the electric field at \(P\) makes an angle \(\theta \) with the x-axis, the value of \(\theta \) would be
\(\frac{\pi }{3}\)
\(\frac{\pi }{3} + {\tan ^{ - 1}}\left( {\frac{{\sqrt 3 }}{2}} \right)\)
\(\frac{{2\pi }}{3}\)
\({\tan ^{ - 1}}\left( {\frac{{\sqrt 3 }}{2}} \right)\)
Question:Electric charges \(q,\,q,\, - 2q\) are placed at the corners of an equilateral triangle \(ABC\) of side \(l\). The magnitude of electric dipole moment of the system is
\(ql\)
\(2ql\)
\(\sqrt 3 ql\)
\(4ql\)
Question:Intensity of an electric field E due to a dipole, depends on distance r as
\(E \propto \frac{1}{{{r^4}}}\)
\(E \propto \frac{1}{{{r^3}}}\)
\(E \propto \frac{1}{{{r^2}}}\)
\(E \propto \frac{1}{r}\)
Question:The ratio of electric fields on the axis and at equator of an electric dipole will be
1:01
2:01
4:01
None of these
Question:A cube of side \(l\) is placed in a uniform field E, where\(E = E\hat i\). The net electric flux through the cube is
\({l^2}E\)
\(4{l^2}E\)
\(6{l^2}E\)
Question:The electric intensity due to an infinite cylinder of radius \(R\) and having charge q per unit length at a distance \(r(r > R)\)from its axis is
Directly proportional to \({r^2}\)
Directly proportional to \({r^3}\)
Inversely proportional to r
Inversely proportional to \({r^2}\)
Question:Separation between the plates of a parallel plate capacitor is \(d\)and the area of each plate is \(A\). When a slab of material of dielectric constant\(k\)and thickness \(t(t < d)\) is introduced between the plates, its capacitance becomes
\(\frac{{{\varepsilon _0}A}}{{d + t\left( {1 - \frac{1}{k}} \right)}}\)
\(\frac{{{\varepsilon _0}A}}{{d + t\left( {1 + \frac{1}{k}} \right)}}\)
\(\frac{{{\varepsilon _0}A}}{{d - t\left( {1 - \frac{1}{k}} \right)}}\)
\(\frac{{{\varepsilon _0}A}}{{d - t\left( {1 + \frac{1}{k}} \right)}}\)
Question:The area of each plate of a parallel plate capacitor is \(100\,c{m^2}\)and the distance between the plates is\(1mm\). It is filled with mica of dielectric 6. The radius of the equivalent capacity of the sphere will be
\(47.7\;m\)
4.77 \(m\)
477 \(m\)
None of the above
Question:One plate of parallel plate capacitor is smaller than other, then charge on smaller plate will be
Less than other
More than other
Equal to other
Will depend upon the medium between them
Question:The electric field between the two spheres of a charged spherical condenser
Is zero
Is constant
Increases with distance from the centre
Decreases with distance from the centre
Question:Two spherical conductors each of capacity \(C\) are charged to potentials \(V\) and \( - V\). These are then connected by means of a fine wire. The loss of energy will be
\(\frac{1}{2}C{V^2}\)
\(C{V^2}\)
\(2C{V^2}\)
Question:The ratio of charge to potential of a body is known as
Capacitance
Conductance
Inductance
Resistance
Question:Two insulated metallic spheres of \(3\mu F\) and \(5\mu F\) capacitances are charged to 300 V and 500V respectively. The energy loss, when they are connected by a wire is
0.012 J
0.0218 J
0.0375 J
3.75 J
Question:If the distance between parallel plates of a capacitor is halved and dielectric constant is doubled then the capacitance
Decreases two times
Increases two times
Increases four times
Remain the same
Question:The work done in placing a charge of \(8 \times {10^{ - 18}}\) coulomb on a condenser of capacity 100 micro-farad is
\(32 \times {10^{ - 32}}\,Joule\)
\(16 \times {10^{ - 32}}\,Joule\)
\(3.1 \times {10^{ - 26}}\,Joule\)
\(4 \times {10^{ - 10}}\,Joule\)
Question:A 4 \(\mu \)F condenser is charged to 400 V and then its plates are joined through a resistance. The heat produced in the resistance is
0.16 J
0.32 J
0.64 J
1.28 J
Question:The capacitor of capacitance \(4\mu F\) and\(6\mu F\) are connected in series. A potential difference of \(500\;volts\) is applied to the outer plates of the two capacitor system. The potential difference across the plates of capacitor of \(4\mu F\) capacitance is
\(500\;volts\)
\(300\;volts\)
\(200\;volts\)
\(250\;volts\)
Question:A condenser having a capacity of 6\(\mu \)F is charged to 100 V and is then joined to an uncharged condenser of \(14\mu F\) and then removed. The ratio of the charges on 6\(\mu \)F and 14\(\mu \)F and the potential of 6\(\mu \)F will be
\(\frac{6}{{14}}\) and \(50\;volt\)
\(\frac{{14}}{6}\) and \(30\;volt\)
\(\frac{6}{{14}}\) and \(30\;volt\)
\(\frac{{14}}{6}\) and 0\(volt\)
Question:A capacitor of \(20\mu F\) is charged to \(500\;volts\) and connected in parallel with another capacitor of \(10\mu F\)and charged to \(200\;volts\). The common potential is
\({\rm{400 }}volts\)
\({\rm{500 }}volts\)
Question:A capacitor of capacity \({C_1}\)is charged upto V volt and then connected to an uncharged capacitor of capacity \({C_2}\). Then final potential difference across each will be
\(\frac{{{C_2}V}}{{{C_1} + {C_2}}}\)
\(\left( {1 + \frac{{{C_2}}}{{{C_1}}}} \right)\,V\)
\(\frac{{{C_1}V}}{{{C_1} + {C_2}}}\)
\(\left( {1 - \frac{{{C_2}}}{{{C_1}}}} \right)\,V\)
Question:A charged particle q is shot towards another charged particle Q which is fixed, with a speed \(\nu \). It approaches Q upto a closest distance r and then returns. If q were given a speed \(2\nu \), the closest distances of approach would be
r
2r
r/2
r/4
Question:The figure gives the electric potential V as a function of distance through five regions on \(x\)-axis. Which of the following is true for the electric field E in these regions
\({E_1} > {E_2} > {E_3} > {E_4} > {E_5}\)
\({E_1} = {E_3} = {E_5}\) and \({E_2} < {E_4}\)
\({E_2} = {E_4} = {E_5}\) and \({E_1} < {E_3}\)
\({E_1} < {E_2} < {E_3} < {E_4} < {E_5}\)
Question:Which of the following graphs shows the variation of electric field E due to a hollow spherical conductor of radius R as a function of distance from the centre of the sphere