MCQOPTIONS
Saved Bookmarks
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.
| 7251. |
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 [BCECE 2005] |
| A. | 150 V/m |
| B. | 125 V/m |
| C. | 120 V/m |
| D. | Zero |
| Answer» D. Zero | |
| 7252. |
Four point +ve charges of same magnitude (Q) are placed at four corners of a rigid square frame as shown in figure. The plane of the frame is perpendicular to \[\]axis. If a ?ve point charge is placed at a distance z away from the above frame (z |
| A. | ? ve charge oscillates along the \[\]axis. |
| B. | It moves away from the frame |
| C. | It moves slowly towards the frame and stays in the plane of the frame |
| D. | It passes through the frame only once. |
| Answer» B. It moves away from the frame | |
| 7253. |
Two infinitely long parallel conducting plates having surface charge densities \[+\sigma \]and\[-\sigma \]respectively, are separated by a small distance. The medium between the plates is vacuum. If \[{{\varepsilon }_{0}}\]is the dielectric permittivity of vacuum, then the electric field in the region between the plates is [AIIMS 2005] |
| A. | \[0\,volts/meter\] |
| B. | \[\frac{\sigma }{2{{\varepsilon }_{o}}}volts/meter\] |
| C. | \[\frac{\sigma }{{{\varepsilon }_{o}}}volts/meter\] |
| D. | \[\frac{2\sigma }{{{\varepsilon }_{o}}}volts/meter\] |
| Answer» D. \[\frac{2\sigma }{{{\varepsilon }_{o}}}volts/meter\] | |
| 7254. |
Three infinitely long charge sheets are placed as shown in figure. The electric field at point P is [IIT-JEE (Screening) 2005] |
| A. | \[\frac{2\sigma }{{{\varepsilon }_{o}}}\]\[\hat{k}\] |
| B. | \[-\frac{2\sigma }{{{\varepsilon }_{o}}}\]\[\hat{k}\] |
| C. | \[\frac{4\sigma }{{{\varepsilon }_{o}}}\]\[\hat{k}\] |
| D. | \[-\frac{4\sigma }{{{\varepsilon }_{o}}}\]\[\hat{k}\] |
| Answer» C. \[\frac{4\sigma }{{{\varepsilon }_{o}}}\]\[\hat{k}\] | |
| 7255. |
Two thin wire rings each having a radius R are placed at a distance d apart with their axes coinciding. The charges on the two rings are \[+q\] and \[-q\]. The potential difference between the centres of the two rings is [AIEEE 2005] |
| A. | Zero |
| B. | \[\frac{Q}{4\pi {{\varepsilon }_{0}}}\,\left[ \frac{1}{R}-\frac{1}{\sqrt{{{R}^{2}}+{{d}^{2}}}} \right]\] |
| C. | \[QR/4\pi {{\varepsilon }_{0}}{{d}^{2}}\] |
| D. | \[\frac{Q}{2\pi {{\varepsilon }_{0}}}\left[ \frac{1}{R}-\frac{1}{\sqrt{{{R}^{2}}+{{d}^{2}}}} \right]\] |
| Answer» E. | |
| 7256. |
Two point charges +8q and \[-2q\] are located at \[x=0\] and \[x=L\] respectively. The location of a point on the x-axis at which the net electric field due to these two point charges is zero is [AIEEE 2005] |
| A. | 8 L |
| B. | 4 L |
| C. | 2 L |
| D. | \[\frac{L}{4}\] |
| Answer» D. \[\frac{L}{4}\] | |
| 7257. |
A charged ball B hangs from a silk thread S, which makes an angle \[\theta \] with a large charged conducting sheet \[P\], as shown in the figure. The surface charge density \[\sigma \] of the sheet is proportional to [AIEEE 2005] |
| A. | \[\sin \theta \] |
| B. | \[\tan \theta \] |
| C. | \[\cos \theta \] |
| D. | \[\cot \theta \] |
| Answer» C. \[\cos \theta \] | |
| 7258. |
Two parallel plates have equal and opposite charge. When the space between them is evacuated, the electric field between the plates is \[2\times {{10}^{5}}V/m\]. When the space is filled with dielectric, the electric field becomes\[1\times {{10}^{5}}V/m\]. The dielectric constant of the dielectric material [MP PET 1989] |
| A. | 1/2 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» D. 3 | |
| 7259. |
Inside a hollow charged spherical conductor, the potential [CPMT 1971; MP PMT 1986; RPMT 1997] |
| A. | Is constant |
| B. | Varies directly as the distance from the centre |
| C. | Varies inversely as the distance from the centre |
| D. | Varies inversely as the square of the distance from the centre |
| Answer» B. Varies directly as the distance from the centre | |
| 7260. |
To charges \[{{q}_{1}}\] and \[{{q}_{2}}\] are placed \[30\,\,cm\] apart, shown in the figure. A third charge \[{{q}_{3}}\]is moved along the arc of a circle of radius \[40\,cm\] from \[C\] to D. The change in the potential energy of the system is \[\frac{{{q}_{3}}}{4\pi {{\varepsilon }_{0}}}k\], where \[k\] is [CBSE PMT 2005] |
| A. | \[8\,{{q}_{2}}\] |
| B. | \[8\,{{q}_{1}}\] |
| C. | \[6{{q}_{2}}\] |
| D. | \[6{{q}_{1}}\] |
| Answer» B. \[8\,{{q}_{1}}\] | |
| 7261. |
The dielectric strength of air at NTP is \[3\times {{10}^{6}}\,V/m\] then the maximum charge that can be given to a spherical conductor of radius 3 m is [Pb. PMT 2001] |
| A. | \[3\times {{10}^{-4}}C\] |
| B. | \[3\times {{10}^{-3}}C\] |
| C. | \[3\times {{10}^{-2}}C\] |
| D. | \[3\times {{10}^{-1}}C\] |
| Answer» C. \[3\times {{10}^{-2}}C\] | |
| 7262. |
An electron experiences a force equal to its weight when placed in an electric field. The intensity of the field will be [MHCET 2004] |
| A. | \[1.7\times {{10}^{-11}}\,N/C\] |
| B. | \[5.0\times {{10}^{-11}}\,N/C\] |
| C. | \[5.5\times {{10}^{-11}}\,N/C\] |
| D. | 56 N/C |
| Answer» D. 56 N/C | |
| 7263. |
An infinite line charge produce a field of \[7.182\times {{10}^{8}}\,N/C\] at a distance of 2 cm. The linear charge density is [MH CET 2004] |
| A. | \[7.27\times {{10}^{-4}}\,C/m\] |
| B. | \[7.98\times {{10}^{-4}}\,C/m\] |
| C. | \[7.11\times {{10}^{-4}}\,C/m\] |
| D. | \[7.04\times {{10}^{-4}}\,C/m\] |
| Answer» C. \[7.11\times {{10}^{-4}}\,C/m\] | |
| 7264. |
A pendulum bob of mass \[30.7\times {{10}^{-6}}\,kg\] and carrying a charge \[2\times {{10}^{-8}}\,C\] is at rest in a horizontal uniform electric field of 20000 V/m. The tension in the thread of the pendulum is \[(g=9.8\,m/{{s}^{2}})\] [UPSEAT 2004] |
| A. | \[3\times {{10}^{-4}}\,N\] |
| B. | \[4\times {{10}^{-4}}\,N\] |
| C. | \[5\times {{10}^{-4}}\,N\] |
| D. | \[6\times {{10}^{-4}}\,N\] |
| Answer» D. \[6\times {{10}^{-4}}\,N\] | |
| 7265. |
A square of side ?a? has charge Q at its centre and charge ?q? at one of the corners. The work required to be done in moving the charge ?q? from the corner to the diagonally opposite corner is [UPSEAT 2004] |
| A. | Zero |
| B. | \[\frac{Qq}{4\pi {{\in }_{0}}a}\] |
| C. | \[\frac{Qq\sqrt{2}}{4\pi {{\in }_{0}}a}\] |
| D. | \[\frac{Qq}{2\pi {{\in }_{0}}a}\] |
| Answer» B. \[\frac{Qq}{4\pi {{\in }_{0}}a}\] | |
| 7266. |
Infinite charges of magnitude q each are lying at x =1, 2, 4, 8... meter on X-axis. The value of intensity of electric field at point x = 0 due to these charges will be [J & K CET 2004] |
| A. | \[12\times {{10}^{9}}q\text{ }N/C\] |
| B. | Zero |
| C. | 6 ´ 109q N/C |
| D. | 4 ´ 109q N/C |
| Answer» B. Zero | |
| 7267. |
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 [DPMT 2004] |
| A. | It will remain in equilibrium |
| B. | It can move inside S, but it cannot cross S |
| C. | It must cross S at some time |
| D. | It may move, but will ultimately return to its starting point |
| Answer» D. It may move, but will ultimately return to its starting point | |
| 7268. |
Figure shows three points A, B and C in a region of uniform electric field \[\overrightarrow{E}\]. The line AB is perpendicular and BC is parallel to the field lines. Then which of the following holds good. Where \[{{V}_{A}},{{V}_{B}}\] and \[{{V}_{C}}\] represent the electric potential at points A, B and C respectively [CPMT 2004; MP PMT 2005] |
| A. | \[{{V}_{A}}={{V}_{B}}={{V}_{C}}\] |
| B. | \[{{V}_{A}}={{V}_{B}}>{{V}_{C}}\] |
| C. | \[{{V}_{A}}={{V}_{B}}<{{V}_{C}}\] |
| D. | \[{{V}_{A}}>{{V}_{B}}={{V}_{C}}\] |
| Answer» C. \[{{V}_{A}}={{V}_{B}}<{{V}_{C}}\] | |
| 7269. |
An electron and a proton are in a uniform electric field, the ratio of their accelerations will be [NCERT 1984; MP PET 2002] |
| A. | Zero |
| B. | Unity |
| C. | The ratio of the masses of proton and electron |
| D. | The ratio of the masses of electron and proton |
| Answer» D. The ratio of the masses of electron and proton | |
| 7270. |
A bullet of mass 2 gm is having a charge of \[2\,\mu C\]. Through what potential difference must it be accelerated, starting from rest, to acquire a speed of \[10\,m/s\] [CBSE PMT 2004] |
| A. | 5 kV |
| B. | 50 kV |
| C. | 5 V |
| D. | 50 V |
| Answer» C. 5 V | |
| 7271. |
Equipotential surfaces associated with an electric field which is increasing in magnitude along the x-direction are [AIIMS 2004] |
| A. | Planes parallel to yz-plane |
| B. | Planes parallel to xy-plane |
| C. | Planes parallel to xz-plane |
| D. | Coaxial cylinders of increasing radii around the x-axis. |
| Answer» B. Planes parallel to xy-plane | |
| 7272. |
Point charge \[{{q}_{1}}=2\mu C\] and \[{{q}_{2}}=-1\,\mu C\] are kept at points \[x=0\] and \[x=6\] respectively. Electrical potential will be zero at points [MP PMT 2004] |
| A. | \[x=2\] and \[x=9\] |
| B. | \[x=1\] and \[x=5\] |
| C. | \[x=4\] and \[x=12\] |
| D. | \[x=-2\] and \[x=2\] |
| Answer» D. \[x=-2\] and \[x=2\] | |
| 7273. |
The radius of nucleus of silver (atomic number = 47) is \[3.4\times {{10}^{-14}}m\]. The electric potential on the surface of nucleus is \[(e=1.6\times {{10}^{-19}}C)\] [Pb. PET 2003] |
| A. | \[1.99\times {{10}^{6}}\,volt\] |
| B. | \[2.9\times {{10}^{6}}\,volt\] |
| C. | \[4.99\times {{10}^{6}}\,volt\] |
| D. | \[0.99\times {{10}^{6}}\,volt\] |
| Answer» B. \[2.9\times {{10}^{6}}\,volt\] | |
| 7274. |
Four charges \[+Q,\,-Q,\,+Q,\,-Q\] are placed at the corners of a square taken in order. At the centre of the square [RPMT 2003] |
| A. | \[E=0,\,V=0\] |
| B. | \[E=0,\,V\ne 0\] |
| C. | \[E\ne 0,\,V=0\] |
| D. | \[E=0,\,V\ne 0\] |
| Answer» B. \[E=0,\,V\ne 0\] | |
| 7275. |
The potential at a distance R/2 from the centre of a conducting sphere of radius R will be [RPMT 2003] |
| A. | 0 |
| B. | \[\frac{Q}{8\pi {{\varepsilon }_{0}}R}\] |
| C. | \[\frac{Q}{4\pi {{\varepsilon }_{0}}R}\] |
| D. | \[\frac{Q}{2\pi {{\varepsilon }_{0}}R}\] |
| Answer» D. \[\frac{Q}{2\pi {{\varepsilon }_{0}}R}\] | |
| 7276. |
A charged particle is suspended in equilibrium in a uniform vertical electric field of intensity 20000 V/m. If mass of the particle is \[9.6\times {{10}^{-16}}\,kg\], the charge on it and excess number of electrons on the particle are respectively \[(g=10\,m/{{s}^{2}})\] [Pb. PMT 2003] |
| A. | \[4.8\times {{10}^{-19}}C,\,3\] |
| B. | \[5.8\times {{10}^{-19}}C,\,4\] |
| C. | \[3.8\times {{10}^{-19}}C,\,2\] |
| D. | \[2.8\times {{10}^{-19}}C,\,1\] |
| Answer» D. \[2.8\times {{10}^{-19}}C,\,1\] | |
| 7277. |
A charge produces an electric field of 1 N/C at a point distant 0.1 m from it. The magnitude of charge is [RPET 2002] |
| A. | \[1.11\times {{10}^{-12}}\,C\] |
| B. | \[9.11\times {{10}^{-12}}\,C\] |
| C. | \[7.11\times {{10}^{-6}}\,C\] |
| D. | None of these |
| Answer» B. \[9.11\times {{10}^{-12}}\,C\] | |
| 7278. |
A conductor with a positive charge |
| A. | Is always at \[+\,ve\] potential |
| B. | Is always at zero potential |
| C. | Is always at negative potential |
| D. | May be at , zero or potential |
| Answer» E. | |
| 7279. |
The wrong statement about electric lines of force is [RPMT 2002] |
| A. | These originate from positive charge and end on negative charge |
| B. | They do not intersect each other at a point |
| C. | They have the same form for a point charge and a sphere |
| D. | They have physical existence |
| Answer» E. | |
| 7280. |
The electric potential inside a conducting sphere [RPMT 2002] |
| A. | Increases from centre to surface |
| B. | Decreases from centre to surface |
| C. | Remains constant from centre to surface |
| D. | Is zero at every point inside |
| Answer» D. Is zero at every point inside | |
| 7281. |
Two plates are at potentials ?10 V and +30 V. If the separation between the plates be 2 cm. The electric field between them is [Pb. PET 2000] |
| A. | 2000 V/m |
| B. | 1000 V/m |
| C. | 500 V/m |
| D. | 3000 V/m |
| Answer» B. 1000 V/m | |
| 7282. |
Three point charges are placed at the corners of an equilateral triangle. Assuming only electrostatic forces are acting [KCET 2002] |
| A. | The system can never be in equilibrium |
| B. | The system will be in equilibrium if the charges rotate about the centre of the triangle |
| C. | The system will be in equilibrium if the charges have different magnitudes and different signs |
| D. | The system will be in equilibrium if the charges have the same magnitudes but different signs |
| Answer» B. The system will be in equilibrium if the charges rotate about the centre of the triangle | |
| 7283. |
Two parallel plates separated by a distance of \[5mm\] are kept at a potential difference of \[50\,V.\] A particle of mass \[{{10}^{-15}}kg\] and charge \[{{10}^{-11}}C\] enters in it with a velocity \[{{10}^{7}}m/s.\] The acceleration of the particle will be [MP PMT 1997] |
| A. | \[{{10}^{8}}m/{{s}^{2}}\] |
| B. | \[5\times {{10}^{5}}m/{{s}^{2}}\] |
| C. | \[{{10}^{5}}m/{{s}^{2}}\] |
| D. | \[2\times {{10}^{3}}m/{{s}^{2}}\] |
| Answer» B. \[5\times {{10}^{5}}m/{{s}^{2}}\] | |
| 7284. |
There is 10 units of charge at the centre of a circle of radius 10m. The work done in moving 1 unit of charge around the circle once is [EAMCET (Med.) 1995; AIIMS 2000; Pb. PMT 2000] |
| A. | Zero |
| B. | 10 units |
| C. | 100 units |
| D. | 1 unit |
| Answer» B. 10 units | |
| 7285. |
Value of potential at a point due to a point charge is [MP PET 1996] |
| A. | Inversely proportional to square of the distance |
| B. | Directly proportional to square of the distance |
| C. | Inversely proportional to the distance |
| D. | Directly proportional to the distance |
| Answer» D. Directly proportional to the distance | |
| 7286. |
Electric potential of earth is taken to be zero because earth is a good [AIIMS 1998; BHU 2002] |
| A. | Insulator |
| B. | Conductor |
| C. | Semiconductor |
| D. | Dielectric |
| Answer» C. Semiconductor | |
| 7287. |
The work done in carrying a charge of \[5\mu \,C\] from a point A to a point B in an electric field is 10mJ. The potential difference \[({{V}_{B}}-{{V}_{A}})\] is then [Haryana CEE 1996] |
| A. | + 2kV |
| B. | ? 2 kV |
| C. | + 200 V |
| D. | ? 200 V |
| Answer» B. ? 2 kV | |
| 7288. |
The magnitude of electric field intensity \[E\] is such that, an electron placed in it would experience an electrical force equal to its weight is given by [CPMT 1975, 80; AFMC 2001; BCECE 2003] |
| A. | \[mge\] |
| B. | \[\frac{mg}{e}\] |
| C. | \[\frac{e}{mg}\] |
| D. | \[\frac{{{e}^{2}}}{{{m}^{2}}}g\] |
| Answer» C. \[\frac{e}{mg}\] | |
| 7289. |
A hollow metal sphere of radius 5cm is charged such that the potential on its surface is 10V. The potential at a distance of 2cm from the centre of the sphere [MP PET 1992; MP PMT 1996] |
| A. | Zero |
| B. | 10 V |
| C. | 4 V |
| D. | 10/3 V |
| Answer» C. 4 V | |
| 7290. |
When one electron is taken towards the other electron, then the electric potential energy of the system [RPET 1999; CBSE PMT 1993, 99; Pb. PMT 1999; BHU 2000, 02] |
| A. | Decreases |
| B. | Increases |
| C. | Remains unchanged |
| D. | Becomes zero |
| Answer» C. Remains unchanged | |
| 7291. |
There are two equipotential surface as shown in figure. The distance between them is r. The charge of ?q coulomb is taken from the surface A to B, the resultant work done will be [MP PMT 1986; CPMT 1986, 88] |
| A. | \[W=\frac{1}{4\pi {{\varepsilon }_{o}}}\frac{q}{r}\] |
| B. | \[W=\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{q}{{{r}^{2}}}\] |
| C. | \[W=-\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{q}{{{r}^{2}}}\] |
| D. | W = zero |
| Answer» E. | |
| 7292. |
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 [MP PMT 1986; 2000] |
| A. | 10 volts |
| B. | 90 volts |
| C. | 1000 volts |
| D. | 3000 volts |
| Answer» B. 90 volts | |
| 7293. |
When a negative charge is taken at a height from earth's surface, then its potential energy [DPMT 2002] |
| A. | Decreases |
| B. | Increases |
| C. | Remains unchanged |
| D. | Will become infinity |
| Answer» C. Remains unchanged | |
| 7294. |
A sphere of 4 cm radius is suspended within a hollow sphere of 6 cm radius. The inner sphere is charged to potential 3 e.s.u. and the outer sphere is earthed. The charge on the inner sphere is [MP PMT 1991] |
| A. | 54 e.s.u. |
| B. | \[\frac{1}{4}\] e.s.u. |
| C. | 30 e.s.u. |
| D. | 36 e.s.u. |
| Answer» E. | |
| 7295. |
A table tennis ball which has been covered with conducting paint is suspended by a silk thread so that it hang between two plates, out of which one is earthed and other is connected to a high voltage generator. This ball |
| A. | Is attracted towards high voltage plate and stays there |
| B. | Hangs without moving |
| C. | Swing backward and forward hitting each plate in turn |
| D. | Is attracted to earthed plate and stays there |
| Answer» D. Is attracted to earthed plate and stays there | |
| 7296. |
A charge of 10 e.s.u. is placed at a distance of 2 cm from a charge of 40 e.s.u. and 4 cm from another charge of 20 e.s.u. The potential energy of the charge 10 e.s.u. is (in ergs) [CPMT 1976; MP PET 1989] |
| A. | 87.5 |
| B. | 112.5 |
| C. | 150 |
| D. | 250 |
| Answer» E. | |
| 7297. |
In the electric field of a point charge \[q\], a certain charge is carried from point \[A\] to \[B\], \[C\], \[D\] and \[E\]. Then the work done [NCERT 1980] |
| A. | Is least along the path \[AB\] |
| B. | Is least along the path \[AD\] |
| C. | Is zero along all the paths \[AB,\ AC,\ AD\] and \[AE\] |
| D. | Is least along \[AE\] |
| Answer» D. Is least along \[AE\] | |
| 7298. |
Work done in moving a positive charge on an equipotential surface is [BCECE 2004] |
| A. | Finite, positive but not zero |
| B. | Finite, negative but not zero |
| C. | Zero |
| D. | Infinite |
| Answer» D. Infinite | |
| 7299. |
The charge given to a hollow sphere of radius 10 cm is \[3.2\times {{10}^{19}}\]coulomb. At a distance of 4 cm from its centre, the electric potential will be [MP PMT 1990] |
| A. | \[28.8\times {{10}^{-9}}\,volts\] |
| B. | \[288\,volts\] |
| C. | 2.88 volts |
| D. | Zero |
| Answer» B. \[288\,volts\] | |
| 7300. |
An electron (charge = \[1.6\times {{10}^{-19}}\] coulomb) is accelerated through a potential of 1,00,000 volts. The energy required by the electron is [MP PET 1989] |
| A. | \[1.6\times {{10}^{-24}}\] joule |
| B. | \[1.6\times {{10}^{-14}}\,\,erg\] |
| C. | \[0.53\times {{10}^{-14}}\]joule |
| D. | \[1.6\times {{10}^{-14}}\] joule |
| Answer» E. | |