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MCQOPTIONS
This section includes 12583 Mcqs, each offering curated multiple-choice questions to sharpen your Joint Entrance Exam - Main (JEE Main) knowledge and support exam preparation. Choose a topic below to get started.
| 7151. |
For a given surface the Gauss's law is stated as . From this we can conclude that [MP PMT 1995] |
| A. | is necessarily zero on the surface |
| B. | is perpendicular to the surface at every point |
| C. | The total flux through the surface is zero |
| D. | The flux is only going out of the surface |
| Answer» D. The flux is only going out of the surface | |
| 7152. |
Total electric flux coming out of a unit positive charge put in air is [MP PET 1995] |
| A. | |
| B. | |
| C. | |
| D. | |
| Answer» C. | |
| 7153. |
An electric charge is placed at the centre of a cube of side . The electric flux on one of its faces will be [MP PMT 1994, 95; DCE 1999, 2001; AIIMS 2001] |
| A. | |
| B. | |
| C. | |
| D. | |
| Answer» B. | |
| 7154. |
A sphere of radius R has a uniform distribution of electric charge in its volume. At a distance x from its centre, for , the electric field is directly proportional to [MP PMT 1994; AIIMS 1997; BCECE 2005] |
| A. | |
| B. | |
| C. | |
| D. | |
| Answer» D. | |
| 7155. |
The electric intensity due to an infinite cylinder of radius and having charge q per unit length at a distance from its axis is [MP PMT 1993; AFMC 2000] |
| A. | Directly proportional to |
| B. | Directly proportional to |
| C. | Inversely proportional to r |
| D. | Inversely proportional to |
| Answer» D. Inversely proportional to | |
| 7156. |
The electric flux for Gaussian surface A that enclose the charged particles in free space is (given ) [KCET 2005] |
| A. | |
| B. | |
| C. | |
| D. | |
| Answer» B. | |
| 7157. |
Two infinite plane parallel sheets separated by a distance have equal and opposite uniform charge densities . Electric field at a point between the sheets is [MP PET 1999] |
| A. | Zero |
| B. | |
| C. | |
| D. | Depends upon the location of the point |
| Answer» C. | |
| 7158. |
An electric dipole is put in north-south direction in a sphere filled with water. Which statement is correct [MP PET 1995] |
| A. | Electric flux is coming towards sphere |
| B. | Electric flux is coming out of sphere |
| C. | Electric flux entering into sphere and leaving the sphere are same |
| D. | Water does not permit electric flux to enter into sphere |
| Answer» D. Water does not permit electric flux to enter into sphere | |
| 7159. |
Consider the charge configuration and spherical Gaussian surface as shown in the figure. When calculating the flux of the electric field over the spherical surface the electric field will be due to [IIT-JEE Screening 2004] |
| A. | |
| B. | Only the positive charges |
| C. | All the charges |
| D. | and |
| Answer» D. and | |
| 7160. |
A charge q is located at the centre of a cube. The electric flux through any face is [CBSE PMT 2003] |
| A. | |
| B. | |
| C. | |
| D. | |
| Answer» B. | |
| 7161. |
Shown below is a distribution of charges. The flux of electric field due to these charges through the surface S is [AIIMS 2003] |
| A. | |
| B. | |
| C. | |
| D. | Zero |
| Answer» C. | |
| 7162. |
If the electric flux entering and leaving an enclosed surface respectively is and the electric charge inside the surface will be [AIEEE 2003] |
| A. | |
| B. | |
| C. | |
| D. | |
| Answer» C. | |
| 7163. |
If a spherical conductor comes out from the closed surface of the sphere then total flux emitted from the surface will be [RPET 2003] |
| A. | (the charge enclosed by surface) |
| B. | (charge enclosed by surface) |
| C. | (charge enclosed by surface) |
| D. | 0 |
| Answer» B. (charge enclosed by surface) | |
| 7164. |
A charge is placed at the centre of a cube. Then the flux passing through one face of cube will be [RPET 2003; MP PET 2003; UPSEAT 2004] |
| A. | |
| B. | |
| C. | |
| D. | |
| Answer» E. | |
| 7165. |
The inward and outward electric flux for a closed surface in units of are respectively and Then the total charge inside the surface is [where permittivity constant] [KCET 2003; MP PMT 2002] |
| A. | C |
| B. | C |
| C. | C |
| D. | C |
| Answer» E. | |
| 7166. |
Gauss?s law should be invalid if [Orissa JEE 2002] |
| A. | There were magnetic monopoles |
| B. | The inverse square law were not exactly true |
| C. | The velocity of light were not a universal constant |
| D. | None of these |
| Answer» C. The velocity of light were not a universal constant | |
| 7167. |
and are point charges located at points as shown in the figure and is a spherical Gaussian surface of radius R. Which of the following is true according to the Gauss?s law [AMU 2002] |
| A. | |
| B. | |
| C. | |
| D. | None of the above |
| Answer» C. | |
| 7168. |
According to Gauss? Theorem, electric field of an infinitely long straight wire is proportional to [RPET 2000; DCE 2000] |
| A. | r |
| B. | |
| C. | |
| D. | |
| Answer» E. | |
| 7169. |
Electric charge is uniformly distributed along a long straight wire of radius 1mm. The charge per cm length of the wire is Q coulomb. Another cylindrical surface of radius 50 cm and length 1m symmetrically encloses the wire as shown in the figure. The total electric flux passing through the cylindrical surface is [MP PET 2001] |
| A. | |
| B. | |
| C. | |
| D. | |
| Answer» C. | |
| 7170. |
The S.I. unit of electric flux is [KCET 2001] |
| A. | Weber |
| B. | Newton per coulomb |
| C. | Volt ´ metre |
| D. | Joule per coulomb |
| Answer» D. Joule per coulomb | |
| 7171. |
It is not convenient to use a spherical Gaussian surface to find the electric field due to an electric dipole using Gauss?s theorem because [AMU 2000] |
| A. | Gauss?s law fails in this case |
| B. | This problem does not have spherical symmetry |
| C. | Coulomb?s law is more fundamental than Gauss?s law |
| D. | Spherical Gaussian surface will alter the dipole moment |
| Answer» C. Coulomb?s law is more fundamental than Gauss?s law | |
| 7172. |
A cylinder of radius R and length L is placed in a uniform electric field E parallel to the cylinder axis. The total flux for the surface of the cylinder is given by [CPMT 1975; RPMT 2002; KCET 2004] |
| A. | |
| B. | |
| C. | |
| D. | Zero |
| Answer» E. | |
| 7173. |
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 [Pb. PMT 2000] |
| A. | \[E\propto {{R}^{-2}}\] |
| B. | \[E\propto {{R}^{-1}}\] |
| C. | \[E\propto \frac{1}{{{R}^{3}}}\] |
| D. | \[E\propto {{R}^{2}}\] |
| Answer» D. \[E\propto {{R}^{2}}\] | |
| 7174. |
The potential at a point, due to a positive charge of \[100\mu C\] at a distance of 9m, is [KCET (Med.) 2000] |
| A. | \[{{10}^{4}}\]V |
| B. | \[{{10}^{5}}\]V |
| C. | \[{{10}^{6}}\]V |
| D. | \[{{10}^{7}}\]V |
| Answer» C. \[{{10}^{6}}\]V | |
| 7175. |
The displacement of a charge Q in the electric field \[E={{e}_{1}}\hat{i}+{{e}_{2}}\hat{j}+{{e}_{3}}\hat{k}\] is \[\hat{r}=a\hat{i}+b\hat{j}\]. The work done is [EAMCET (Engg.) 2000] |
| A. | \[Q(a{{e}_{1}}+b{{e}_{2}})\] |
| B. | \[Q\sqrt{{{\left( a{{e}_{1}} \right)}^{2}}+{{\left( b{{e}_{2}} \right)}^{2}}}\] |
| C. | \[Q({{e}_{1}}+{{e}_{2}})\sqrt{{{a}^{2}}+{{b}^{2}}}\] |
| D. | \[Q(\sqrt{e_{1}^{2}+e_{2}^{2})}\ (a+b)\] |
| Answer» B. \[Q\sqrt{{{\left( a{{e}_{1}} \right)}^{2}}+{{\left( b{{e}_{2}} \right)}^{2}}}\] | |
| 7176. |
Three identical point charges, as shown are placed at the vertices of an isosceles right angled triangle. Which of the numbered vectors coincides in direction with the electric field at the mid-point M of the hypotenuse [AMU 2000] |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |
| 7177. |
Two positive point charges of \[12\mu C\] and \[8\mu C\] are 10cm apart. The work done in bringing them 4 cm closer is [AMU 2000] |
| A. | 5.8 J |
| B. | 5.8 eV |
| C. | 13 J |
| D. | 13 eV |
| Answer» D. 13 eV | |
| 7178. |
Ten electrons are equally spaced and fixed around a circle of radius R. Relative to V = 0 at infinity, the electrostatic potential V and the electric field E at the centre C are [AMU 2000] |
| A. | \[V\ne 0\] and \[\vec{E}\ne 0\] |
| B. | \[V\ne 0\] and \[\vec{E}=0\] |
| C. | \[V=0\] and \[\vec{E}=0\] |
| D. | \[V=0\] and \[\vec{E}\ne 0\] |
| Answer» C. \[V=0\] and \[\vec{E}=0\] | |
| 7179. |
Electric field strength due to a point charge of \[5\mu C\] at a distance of 80 cm from the charge is [CBSE PMT 2000] |
| A. | \[8\times {{10}^{4}}\]N/C |
| B. | \[7\times {{10}^{4}}\]N/C |
| C. | \[5\times {{10}^{4}}\]N/C |
| D. | \[4\times {{10}^{4}}\]N/C |
| Answer» C. \[5\times {{10}^{4}}\]N/C | |
| 7180. |
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 \[\left[ \frac{1}{4\pi {{\varepsilon }_{0}}}=9\times {{10}^{9}}\frac{N\text{-}{{m}^{2}}}{{{C}^{2}}} \right]\] [EAMCET (Med.) 2000] |
| A. | \[9\times {{10}^{4}}\]V |
| B. | \[18\times {{10}^{4}}\]V |
| C. | \[36\times {{10}^{4}}\]V |
| D. | \[36\times {{10}^{-4}}\]V |
| Answer» D. \[36\times {{10}^{-4}}\]V | |
| 7181. |
The electric field due to a charge at a distance of 3 m from it is 500 N/coulomb. The magnitude of the charge is \[\left[ \frac{1}{4\pi {{\varepsilon }_{0}}}=9\times {{10}^{9}}\frac{N-{{m}^{2}}}{coulom{{b}^{2}}} \right]\] [MP PMT 2000] |
| A. | 2.5 micro-coulomb |
| B. | 2.0 micro-coulomb |
| C. | 1.0 micro-coulomb |
| D. | 0.5 micro-coulomb |
| Answer» E. | |
| 7182. |
If a unit positive charge is taken from one point to another over an equipotential surface, then [KCET 1994; CPMT 1997; CBSE PMT 2000] |
| A. | Work is done on the charge |
| B. | Work is done by the charge |
| C. | Work done is constant |
| D. | No work is done |
| Answer» E. | |
| 7183. |
An electron enters between two horizontal plates separated by 2mm and having a potential difference of 1000V. The force on electron is [JIPMER 1999] |
| A. | \[8\times {{10}^{-12}}\]N |
| B. | \[8\times {{10}^{-14}}\]N |
| C. | \[8\times {{10}^{9}}\] N |
| D. | \[8\times {{10}^{14}}\] N |
| Answer» C. \[8\times {{10}^{9}}\] N | |
| 7184. |
Electric charges of \[+10\mu C,\ +5\mu C,\ -3\mu C\] and \[+8\mu C\] are placed at the corners of a square of side \[\sqrt{2}\]m. the potential at the centre of the square is [KCET (Engg./Med.) 1999] |
| A. | 1.8 V |
| B. | \[1.8\times {{10}^{6}}\] V |
| C. | \[1.8\times {{10}^{5}}\]V |
| D. | \[1.8\times {{10}^{4}}\]V |
| Answer» D. \[1.8\times {{10}^{4}}\]V | |
| 7185. |
When a proton is accelerated through 1V, then its kinetic energy will be [CBSE PMT 1999] |
| A. | 1840 eV |
| B. | 13.6 eV |
| C. | 1 eV |
| D. | 0.54 eV |
| Answer» D. 0.54 eV | |
| 7186. |
A proton is accelerated through 50,000 V. Its energy will increase by [JIPMER 1999] |
| A. | 5000 eV |
| B. | \[8\times {{10}^{-15}}\]J |
| C. | 5000 J |
| D. | 50,000 J |
| Answer» C. 5000 J | |
| 7187. |
The ratio of momenta of an electron and an a-particle which are accelerated from rest by a potential difference of 100 volt is [UPSEAT 1999] |
| A. | 1 |
| B. | \[\sqrt{\frac{2{{m}_{e}}}{{{m}_{\alpha }}}}\] |
| C. | \[\sqrt{\frac{{{m}_{e}}}{{{m}_{\alpha }}}}\] |
| D. | \[\sqrt{\frac{{{m}_{e}}}{2{{m}_{\alpha }}}}\] |
| Answer» E. | |
| 7188. |
An oil drop having charge \[2e\] is kept stationary between two parallel horizontal plates 2.0 cm apart when a potential difference of 12000 volts is applied between them. If the density of oil is\[900kg/{{m}^{3}}\], the radius of the drop will be [AMU 1999] |
| A. | \[2.0\times {{10}^{-6}}m\] |
| B. | \[1.7\times {{10}^{-6}}m\] |
| C. | \[1.4\times {{10}^{-6}}m\] |
| D. | \[1.1\times {{10}^{-6}}m\] |
| Answer» C. \[1.4\times {{10}^{-6}}m\] | |
| 7189. |
If a charged spherical conductor of radius \[10\,cm\]has potential \[V\] at a point distant \[5\,cm\] from its centre, then the potential at a point distant \[15\,cm\] from the centre will be [SCRA 1998; JIPMER 2001, 02] |
| A. | \[\frac{1}{3}V\] |
| B. | \[\frac{2}{3}V\] |
| C. | \[\frac{3}{2}V\] |
| D. | \[3V\] |
| Answer» C. \[\frac{3}{2}V\] | |
| 7190. |
Two unlike charges of magnitude \[q\] are separated by a distance \[2d\]. The potential at a point midway between them is [JIPMER 1999] |
| A. | Zero |
| B. | \[\frac{1}{4\pi {{\varepsilon }_{0}}}\] |
| C. | \[\frac{1}{4\pi {{\varepsilon }_{0}}}.\frac{q}{d}\] |
| D. | \[\frac{1}{4\pi {{\varepsilon }_{0}}}.\frac{2q}{{{d}^{2}}}\] |
| Answer» B. \[\frac{1}{4\pi {{\varepsilon }_{0}}}\] | |
| 7191. |
A hollow metal sphere of radius 5 cm is charged so that the potential on its surface is 10 V. The potential at the centre of the sphere is [IIT 1983; MNR 1990; MP PET/PMT 2000; DPMT 2004] |
| A. | 0 V |
| B. | 10 V |
| C. | Same as at point 5 cm away from the surface |
| D. | Same as at point 25 cm away from the surface |
| Answer» C. Same as at point 5 cm away from the surface | |
| 7192. |
Two point charges of \[20\,\mu \,C\] and \[80\,\mu \,C\] are \[10\,cm\] apart. Where will the electric field strength be zero on the line joining the charges from \[20\,\mu \,C\] charge [RPET 1997] |
| A. | \[0.1\,m\] |
| B. | \[0.04\,m\] |
| C. | \[0.033\,m\] |
| D. | \[0.33\,m\] |
| Answer» D. \[0.33\,m\] | |
| 7193. |
Point charges \[+4q,\,-q\] and \[+4q\] are kept on the \[x-\]axis at points \[x=0,\,x=a\] and \[x=2a\] respectively, then [CBSE PMT 1992] |
| A. | Only \[q\] is in stable equilibrium |
| B. | None of the charges are in equilibrium |
| C. | All the charges are in unstable equilibrium |
| D. | All the charges are in stable equilibrium |
| Answer» D. All the charges are in stable equilibrium | |
| 7194. |
A sphere of radius \[1\,cm\] has potential of \[8000\,V\], then energy density near its surface will be [RPET 1999] |
| A. | \[64\times {{10}^{5}}J/{{m}^{3}}\] |
| B. | \[8\times {{10}^{3}}J/{{m}^{3}}\] |
| C. | \[32\,J/{{m}^{3}}\] |
| D. | \[2.83\,J/{{m}^{3}}\] |
| Answer» E. | |
| 7195. |
Four charges are placed on corners of a square as shown in figure having side of \[5\,cm\]. If Q is one microcoulomb, then electric field intensity at centre will be [RPET 1999] |
| A. | \[1.02\times {{10}^{7}}N/C\] upwards |
| B. | \[2.04\times {{10}^{7}}N/C\] downwards |
| C. | \[2.04\times {{10}^{7}}N/C\] upwards |
| D. | \[1.02\times {{10}^{7}}N/C\] downwards |
| Answer» B. \[2.04\times {{10}^{7}}N/C\] downwards | |
| 7196. |
A charged water drop whose radius is \[0.1\,\mu m\] is in equilibrium in an electric field. If charge on it is equal to charge of an electron, then intensity of electric field will be \[(g=10\,m{{s}^{-1}})\] [RPET 1997] |
| A. | \[1.61\,N/C\] |
| B. | \[26.2\,N/C\] |
| C. | \[262\,N/C\] |
| D. | \[1610\,N/C\] |
| Answer» D. \[1610\,N/C\] | |
| 7197. |
A hollow insulated conducting sphere is given a positive charge of \[10\,\mu \,C\]. What will be the electric field at the centre of the sphere if its radius is 2 meters [CBSE PMT 1998] |
| A. | Zero |
| B. | \[5\,\mu \,C{{m}^{-2}}\] |
| C. | \[20\,\mu \,C{{m}^{-2}}\] |
| D. | \[8\,\mu \,C{{m}^{-2}}\] |
| Answer» B. \[5\,\mu \,C{{m}^{-2}}\] | |
| 7198. |
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 [KCET 1994, 2000] |
| A. | \[q/{{b}^{2}}\] |
| B. | \[q/2{{b}^{2}}\] |
| C. | \[32q/{{b}^{2}}\] |
| D. | Zero |
| Answer» E. | |
| 7199. |
An electron of mass \[{{m}_{e}}\] initially at rest moves through a certain distance in a uniform electric field in time \[{{t}_{1}}\]. A proton of mass \[{{m}_{p}}\] also initially at rest takes time \[{{t}_{2}}\] to move through an equal distance in this uniform electric field. Neglecting the effect of gravity, the ratio of \[{{t}_{2}}/{{t}_{1}}\] is nearly equal to [IIT 1997 Cancelled] |
| A. | 1 |
| B. | \[{{({{m}_{p}}/{{m}_{e}})}^{1/2}}\] |
| C. | \[{{({{m}_{e}}/{{m}_{p}})}^{1/2}}\] |
| D. | 1836 |
| Answer» C. \[{{({{m}_{e}}/{{m}_{p}})}^{1/2}}\] | |
| 7200. |
The electric potential \[V\] at any point O (x, y, z all in metres) in space is given by \[V=4{{x}^{2}}\,volt\]. The electric field at the point \[(1m,\,0,\,2m)\] in \[volt/metre\] is [IIT 1992; RPET 1999; MP PMT 2001] |
| A. | 8 along negative \[X-\]axis |
| B. | 8 along positive \[X-\]axis |
| C. | 16 along negative \[X-\]axis |
| D. | 16 along positive \[Z-\]axis |
| Answer» B. 8 along positive \[X-\]axis | |