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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.
| 12151. |
A frictionless wire AB is fixed on a sphere of radius R. A very small spherical ball slips on this wire. The time taken by this ball to slip from A to B is |
| A. | \[\frac{2\sqrt{gR}}{g\cos \theta }\] |
| B. | \[2\sqrt[{}]{gR,}\]\[\frac{\cos \theta }{2}\] |
| C. | \[\sqrt[2]{\frac{R}{g}}\] |
| D. | \[\frac{gR}{\sqrt{g\cos \theta }}\] |
| Answer» D. \[\frac{gR}{\sqrt{g\cos \theta }}\] | |
| 12152. |
Two bikes A and B start from a point. A moves with uniform speed 40 m/s and B starts from rest with uniform acceleration \[2\,m/{{s}^{2}}\]. If B starts at \[t=10\] and A starts from the same point at \[t=10\] s, then the time during the journey in which A was ahead of B is |
| A. | 20 s |
| B. | 8 s |
| C. | 10 s |
| D. | A is never ahead of B |
| Answer» E. | |
| 12153. |
Which is different from others by units [Orissa JEE 2002] |
| A. | (a) Phase difference |
| B. | Mechanical equivalent |
| C. | Loudness of sound |
| D. | Poisson's ratio |
| Answer» E. | |
| 12154. |
In C.G.S. system the magnitutde of the force is 100 dynes. In another system where the fundamental physical quantities are kilogram, metre and minute, the magnitude of the force is [EAMCET 2001] |
| A. | 0.036 |
| B. | 0.36 |
| C. | 3.6 |
| D. | 36 |
| Answer» D. 36 | |
| 12155. |
'Torr' is the unit of [RPMT 1999, 2000] |
| A. | Pressure |
| B. | Volume |
| C. | Density |
| D. | Flux |
| Answer» B. Volume | |
| 12156. |
One pico Farad is equal to |
| A. | \[{{10}^{-24}}F\] |
| B. | \[{{10}^{-18}}F\] |
| C. | \[{{10}^{-12}}F\] |
| D. | \[{{10}^{-6}}F\] |
| Answer» D. \[{{10}^{-6}}F\] | |
| 12157. |
\[Kilowatt-hour\] is a unit of [NCERT 1975; AFMC 1991] |
| A. | Electrical charge |
| B. | Energy |
| C. | Power |
| D. | Force |
| Answer» C. Power | |
| 12158. |
Which of the following represents a volt [CPMT 1990; AFMC 1991] |
| A. | Joule/second |
| B. | Watt/Ampere |
| C. | Watt/Coulomb |
| D. | Coulomb/Joule |
| Answer» C. Watt/Coulomb | |
| 12159. |
The magnitude of any physical quantity |
| A. | Depends on the method of measurement |
| B. | Does not depend on the method of measurement |
| C. | Is more in SI system than in CGS system |
| D. | Directly proportional to the fundamental units of mass, length and time |
| Answer» C. Is more in SI system than in CGS system | |
| 12160. |
A cube has numerically equal volume and surface area. The volume of such a cube is [CPMT 1971, 74] |
| A. | 216 units |
| B. | 1000 units |
| C. | 2000 units |
| D. | 3000 units |
| Answer» B. 1000 units | |
| 12161. |
The resistance of a metal is given by \[R=\frac{V}{I}\]where V is potential difference and I is the current. In a circuit the potential difference across resistance is \[V=(8\pm 0.5)V\] and current in resistance \[I=(2\pm 0.2)A\]. What is the value of resistance with its percentage error? |
| A. | \[4\Omega \pm 16.25%\] |
| B. | \[(4\pm 0.7)\Omega \] |
| C. | \[4\Omega \pm 0.7%\] |
| D. | \[4\Omega \pm 7%\] |
| Answer» B. \[(4\pm 0.7)\Omega \] | |
| 12162. |
Error in the measurement of radius of a sphere is 1 %. Then error in the measurement of volume is |
| A. | 0.01 |
| B. | 0.05 |
| C. | 0.03 |
| D. | 0.08 |
| Answer» D. 0.08 | |
| 12163. |
In a simple pendulum experiment, the maximum percentage error in the measurement of length is 2% and that in the observation of the time- period is 3%. Then the maximum percentage error in determination of the acceleration due to gravity g is |
| A. | 0.05 |
| B. | 0.06 |
| C. | 0.01 |
| D. | 0.08 |
| Answer» E. | |
| 12164. |
An atomic clock has an accuracy of 1 part is \[{{10}^{10}}\] If two such clocks are operated with precision, then after running for 2500 years these will record a difference of nearly. |
| A. | 1 sec |
| B. | 8 sec |
| C. | 5 sec |
| D. | 10 sec |
| Answer» C. 5 sec | |
| 12165. |
Unit of magnetic moment is |
| A. | ampere-\[metr{{e}^{2}}\] |
| B. | ampere-metre |
| C. | weber-\[metr{{e}^{2}}\] |
| D. | weber/metre |
| Answer» B. ampere-metre | |
| 12166. |
A wire has a mass \[0.3\pm 0.003\text{ }g\], radius \[0.5\pm 0.005\text{ }mm\] and length \[6\pm 0.06\text{ }on\]. The maximum percentage error in the measurement of its density is |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» E. | |
| 12167. |
If x and R stands for distance. Then which of the following is dimensionally same as\[\int{\frac{Rdx}{{{x}^{2}}}}\]? |
| A. | \[R{{x}^{2}}\] |
| B. | \[2xR\] |
| C. | \[\frac{R}{x}\] |
| D. | \[-\frac{{{R}^{2}}}{x}\] |
| Answer» D. \[-\frac{{{R}^{2}}}{x}\] | |
| 12168. |
If velocity (V), force (F) and energy (E) are taken as fundamental units, then dimensional formula for mass will be |
| A. | \[{{V}^{-2}}{{F}^{0}}{{E}^{3}}\] |
| B. | \[{{V}^{0}}F{{E}^{2}}\] |
| C. | \[V{{F}^{-2}}{{E}^{0}}\] |
| D. | \[{{V}^{-2}}{{F}^{0}}E\] |
| Answer» E. | |
| 12169. |
The pitch and the number of circular scale divisions in a screw gauge with least count 0.02 mm are respectively |
| A. | 1mm and 100 |
| B. | 0.5 mm and 50 |
| C. | 1 mm and 50 |
| D. | 0.5 mm and 100 |
| Answer» D. 0.5 mm and 100 | |
| 12170. |
A physical quantity x depends on quantities y and z as follows: \[x=Ay+B\text{ }tan\text{ }Cz\], where A, B and C are constants. Which of the following do not have the same dimensions : |
| A. | x and B |
| B. | C and \[{{z}^{-1}}\] |
| C. | y and B/A |
| D. | x and A |
| Answer» E. | |
| 12171. |
The displacement of a body at a particular second n is given by the expression \[{{S}_{nth}}=u+\frac{a}{2}(2n-1)\]. The dimensional formula of \[{{S}_{nth}}\] in this equation is |
| A. | \[[{{M}^{1}}{{L}^{0}}{{T}^{1}}]\] |
| B. | \[[{{M}^{0}}{{L}^{1}}{{T}^{0}}]\] |
| C. | \[[{{M}^{0}}{{L}^{1}}{{T}^{-1}}]\] |
| D. | \[[{{M}^{0}}{{L}^{0}}{{T}^{0}}]\] |
| Answer» D. \[[{{M}^{0}}{{L}^{0}}{{T}^{0}}]\] | |
| 12172. |
In a new system of units, the fundamental quantities mass, length and time are replaced by acceleration 'a', density \['\rho '\] and frequency\[f\]. The dimensional formula for force in this system is |
| A. | \[[\rho {{a}^{4}}f]\] |
| B. | \[[\rho {{a}^{4}}{{f}^{-6}}]\] |
| C. | \[[{{\rho }^{-1}}{{a}^{-4}}{{f}^{6}}]\] |
| D. | \[[{{\rho }^{-1}}{{a}^{-4}}{{f}^{6}}]\] |
| Answer» C. \[[{{\rho }^{-1}}{{a}^{-4}}{{f}^{6}}]\] | |
| 12173. |
A student measures the time period of 100 oscillations of a simple pendulum four times. The data set is 90 s, 91 s, 95 s and 92 s. If the minimum division in the measuring clock is 1 s, then the reported mean time should be |
| A. | \[92\pm 2s\] |
| B. | \[92\pm 5.0s\] |
| C. | \[92\pm 1.8s\] |
| D. | \[92\pm 3s\] |
| Answer» B. \[92\pm 5.0s\] | |
| 12174. |
The mass of a body is 20.000 g and its volume is 10.00 \[c{{m}^{3}}\]. If the measured values are expressed to the correct significant figures, find the maximum error in the value of density in \[(g\,c{{m}^{-3}})\]. |
| A. | 0.003 |
| B. | 0.001 |
| C. | 0.004 |
| D. | 0.002 |
| Answer» E. | |
| 12175. |
Suppose refractive index \[\mu \] is given as\[\mu =A+\frac{B}{\lambda _{{}}^{2}}\] where A and B are constants and \[\lambda \] is wavelength, then dimensions of B are same as that of |
| A. | Wavelength |
| B. | Volume |
| C. | Pressure |
| D. | Area |
| Answer» E. | |
| 12176. |
Force F is given in terms of time \[t\] and distance \[x\] by F =A sin C\[t\] + B cos\[Dx\]. Then the dimensions of \[A/B\] and \[C/D\] are |
| A. | \[[M_{{}}^{0}L_{{}}^{0}T_{{}}^{0}],[M_{{}}^{0}L_{{}}^{0}T_{{}}^{-1}]\] |
| B. | \[[M_{{}}^{{}}L_{{}}^{{}}T_{{}}^{-2}],[M_{{}}^{0}L_{{}}^{-1}T_{{}}^{0}]\] |
| C. | \[[M_{{}}^{0}L_{{}}^{0}T_{{}}^{0}],[M_{{}}^{0}L_{{}}^{{}}T_{{}}^{-1}]\] |
| D. | \[[M_{{}}^{0}L_{{}}^{1}T_{{}}^{-1}],[M_{{}}^{0}L_{{}}^{0}T_{{}}^{0}]\] |
| Answer» D. \[[M_{{}}^{0}L_{{}}^{1}T_{{}}^{-1}],[M_{{}}^{0}L_{{}}^{0}T_{{}}^{0}]\] | |
| 12177. |
If the susceptibility of dia, para and ferromagnetic materials are\[{{\chi }_{d,\,}}\,{{\chi }_{p,}}\,{{\chi }_{f}}\] respectively, then |
| A. | \[{{\chi }_{d}}<{{\chi }_{p}}<{{\chi }_{f}}\] |
| B. | \[{{\chi }_{d}}<{{\chi }_{f}}<{{\chi }_{p}}\] |
| C. | \[{{\chi }_{f}}<{{\chi }_{d}}<{{\chi }_{p}}\] |
| D. | \[{{\chi }_{f}}<{{\chi }_{p}}<{{\chi }_{d}}\] |
| Answer» B. \[{{\chi }_{d}}<{{\chi }_{f}}<{{\chi }_{p}}\] | |
| 12178. |
A coil in the shape of an equilateral triangle of side l is suspended between the pole pieces of a permanent magnet such that \[\vec{B}\] is in plane of the coil. If due to a current i in the triangle a torque \[\tau \] acts on it, the side l of the triangle is |
| A. | \[\frac{2}{\sqrt{3}}{{\left( \frac{\tau }{B.i} \right)}^{\frac{1}{2}}}\] |
| B. | \[2{{\left( \frac{\tau }{\sqrt{3}B.i} \right)}^{\frac{1}{2}}}\] |
| C. | \[\frac{2}{\sqrt{3}}\left( \frac{\tau }{B.i} \right)\] |
| D. | \[\frac{1}{\sqrt{3}}\frac{\tau }{B.i}\] |
| Answer» C. \[\frac{2}{\sqrt{3}}\left( \frac{\tau }{B.i} \right)\] | |
| 12179. |
A magnetising field of\[2\times {{10}^{3}}\,amp/m\] produces a magnetic flux density of \[8\pi \,\,Tesla\] in an iron rod. The relative permeability of the rod will be - |
| A. | \[{{10}^{2}}\] |
| B. | \[{{10}^{0}}\] |
| C. | \[{{10}^{4}}\] |
| D. | \[{{10}^{1}}\] |
| Answer» D. \[{{10}^{1}}\] | |
| 12180. |
In end on and broadside on position of a deflection magnetometer, if \[{{\theta }_{1}}\] and \[{{\theta }_{2}}\] are the deflections produced by short magnets at equal distances, then \[\tan \,{{\theta }_{1}}/\tan {{\theta }_{2}}\] is |
| A. | 0.0840277777777778 |
| B. | 0.0430555555555556 |
| C. | 0.0423611111111111 |
| D. | 0.167361111111111 |
| Answer» B. 0.0430555555555556 | |
| 12181. |
A 30 cm long bar magnet is placed in the magnetic meridian with its north pole pointing south. The neutral point is obtained at a distance of 40cm from the center of the magnet. Find the pole strength of the magnet. The horizontal component of earth's magnetic field is 0.34 gauss. |
| A. | 25.7 Am |
| B. | 23.7 Am |
| C. | 28.7 Am |
| D. | 26.7 Am |
| Answer» E. | |
| 12182. |
A long straight horizontal cable carries a current of 2.5 A in the direction \[10{}^\circ \] south of west to \[10{}^\circ \] north of east. The magnetic meridian of the place happens to be \[10{}^\circ \] west of the geographic meridian. The earth's magnetic field at the location is 0.33 Gauss, and the angle of dip is zero. Locate the line of neutral points. (Ignore the thickness of the cable). |
| A. | 1.5 cm |
| B. | 2.5 cm |
| C. | 3.5 cm |
| D. | 2.0 cm |
| Answer» B. 2.5 cm | |
| 12183. |
The magnetic needle of a tangent galvanometer is deflected at an angle \[30{}^\circ \] due to a magnet. The horizontal component of earth's magnetic field \[0.34\times {{10}^{-4}}\,T\] is along the plane of the coil. The magnetic intensity is |
| A. | \[1.96\times {{10}^{-4}}\,T\] |
| B. | \[1.96\times {{10}^{-5}}\,T\] |
| C. | \[1.96\times {{10}^{4}}\,T\] |
| D. | \[1.96\times {{10}^{5}}\,T\] |
| Answer» C. \[1.96\times {{10}^{4}}\,T\] | |
| 12184. |
The true value of angle of dip at a place is \[60{}^\circ \], the apparent dip in a plane inclined at an angle of \[30{}^\circ \] with magnetic meridian is |
| A. | \[{{\tan }^{-1}}\frac{1}{2}\] |
| B. | \[{{\tan }^{-1}}(2)\] |
| C. | \[{{\tan }^{-1}}\left( \frac{2}{3} \right)\] |
| D. | \[{{\tan }^{-1}}\left( \frac{\sqrt{3}}{4} \right)\] |
| Answer» C. \[{{\tan }^{-1}}\left( \frac{2}{3} \right)\] | |
| 12185. |
The length of a magnet is large compared to its width and breadth. The time period of its oscillation in a vibration magnetometer is 2 s. The magnet is cut along its length into three equal parts and three parts are then placed on each other with their like poles together. The time period of this combination will be |
| A. | 2s |
| B. | \[2/3s\] |
| C. | \[2\sqrt{3\,}s\] |
| D. | \[2/\sqrt{3\,}s\] |
| Answer» C. \[2\sqrt{3\,}s\] | |
| 12186. |
A dip circle is so set that its needle moves freely in the magnetic meridian. In this position, the angle of dip is \[40{}^\circ \]. Now the dip circle is rotated so that the plane in which the needle moves makes an angle of \[30{}^\circ \] with the magnetic meridian. In this position, the needle will dip by an angle |
| A. | \[{{40}^{o}}\] |
| B. | \[30{}^\circ \] |
| C. | more than \[40{}^\circ \] |
| D. | less than \[{{40}^{o}}\] |
| Answer» E. | |
| 12187. |
The magnetic field of earth at the equator i approximately \[4\times {{10}^{-5}}T\]. The radius of earth is\[6.4\times {{10}^{6}}m\]. Then the dipole moment of the earth will be nearly of the order of: |
| A. | \[{{10}^{23}}\,A\,m\] |
| B. | \[{{10}^{20}}\,A\,{{m}^{2}}\] |
| C. | \[{{10}^{16}}\,A\,{{m}^{2}}\] |
| D. | \[{{10}^{10}}\,A\,{{m}^{2}}\] |
| Answer» B. \[{{10}^{20}}\,A\,{{m}^{2}}\] | |
| 12188. |
Which of the following is responsible for the earth?s magnetic field? |
| A. | convective currents in earth?s core. |
| B. | Diversive current in earth?s core. |
| C. | Rotational motion of earth. |
| D. | Translational motion of earth. |
| Answer» B. Diversive current in earth?s core. | |
| 12189. |
A steel wire of length \[\ell \] has a magnetic moment M. It is bent in L-shape. The new magnetic moment is |
| A. | M |
| B. | \[\frac{M}{\sqrt{2}}\] |
| C. | \[\frac{M}{2}\] |
| D. | \[2M\] |
| Answer» C. \[\frac{M}{2}\] | |
| 12190. |
The figure below shows the north and south poles of a permanent magnet in which n turn coil of area of cross-section A is resting, such that for a current i passed through the coil, the plane of the coil makes an angle \[\theta \] with respect to the direction of magnetic field B. If the plane of the magnetic field and the coil are horizontal and vertical respectively, the torque on the coil will be |
| A. | \[\tau =niAB\,\cos \theta \] |
| B. | \[\tau =niAB\,\sin \theta \] |
| C. | \[\tau =niAB\,\] |
| D. | None of the above, since the magnetic field is radial. |
| Answer» B. \[\tau =niAB\,\sin \theta \] | |
| 12191. |
A magnet of magnetic moment \[50\hat{i}\,\,A-{{m}^{2}}\]is placed along the x-axis in a magnetic field\[\overset{\to }{\mathop{B}}\,=(0.5\hat{i}+3.0\hat{j})T\]. The torque acting on the magnet is |
| A. | \[175\,\hat{k}\,N-m\] |
| B. | \[150\,\hat{k}\,N-m\] |
| C. | \[75\,\hat{k}\,N-m\] |
| D. | \[25\sqrt{37}\,\hat{k}\,\,N-m\] |
| Answer» C. \[75\,\hat{k}\,N-m\] | |
| 12192. |
Two isolated point poles of strength 30 A-m and 60 A-m are placed at a distance of 0.3m. The force of repulsion is |
| A. | \[2\times {{10}^{-3}}N\] |
| B. | \[2\times {{10}^{-4}}N\] |
| C. | \[2\times {{10}^{5}}N\] |
| D. | \[2\times {{10}^{-5}}N\] |
| Answer» B. \[2\times {{10}^{-4}}N\] | |
| 12193. |
Curie-Weiss law is obeyed by iron at a temperature...... [KCET 2004] |
| A. | Below Curie temperature |
| B. | Above Curie temperature |
| C. | At Curie temperature only |
| D. | At all temperatures |
| Answer» C. At Curie temperature only | |
| 12194. |
In the case of bar magnet, lines of magnetic induction [CPMT 1975; CBSE PMT 1990] |
| A. | Start from the north pole and end at the south pole |
| B. | Run continuously through the bar and outside |
| C. | Emerge in circular paths from the middle of the bar |
| D. | Are produced only at the north pole like rays of light from a bulb |
| Answer» C. Emerge in circular paths from the middle of the bar | |
| 12195. |
If a magnetic substance is kept in a magnetic field, then which of the following is thrown out [DCE 1999, 2001] |
| A. | Paramagnetic |
| B. | Ferromagnetic |
| C. | Diamagnetic |
| D. | Antiferromagnetic |
| Answer» D. Antiferromagnetic | |
| 12196. |
Substances in which the magnetic moment of a single atom is not zero, is known as [AFMC 1999] |
| A. | Diamagnetism |
| B. | Ferromagnetism |
| C. | Paramagnetism |
| D. | Ferrimagnetism |
| Answer» D. Ferrimagnetism | |
| 12197. |
Vibration magnetometer is used for comparing [MP PET/PMT 1988] |
| A. | Magnetic fields |
| B. | Earth's field |
| C. | Magnetic moments |
| D. | All of the above |
| Answer» E. | |
| 12198. |
The magnetic potential at a point on the axial line of a bar magnet of dipole moment M is V. What is the magnetic potential due to a bar magnet of dipole moment \[\frac{M}{4}\] at the same point [MH CET 2004] |
| A. | \[4\,V\] |
| B. | \[2\,V\] |
| C. | \[\frac{V}{2}\] |
| D. | \[\frac{V}{4}\] |
| Answer» E. | |
| 12199. |
Two identical bar magnets are placed on above the other such that they are mutually perpendicular and bisect each other. The time period of this combination in a horizontal magnetic field is T. The time period of each magnet in the same field is [CPMT 2005] |
| A. | \[\sqrt{2}\,T\] |
| B. | \[{{2}^{\frac{1}{4}}}T\] |
| C. | \[{{2}^{-\frac{1}{4}}}T\] |
| D. | \[{{2}^{-\frac{1}{2}}}T\] |
| Answer» D. \[{{2}^{-\frac{1}{2}}}T\] | |
| 12200. |
Assertion : We cannot think of magnetic field configuration with three poles. Reason : A bar magnet does exert a torque on itself due to its own field. [AIIMS 2002] |
| A. | If both assertion and reason are true and the reason is the correct explanation of the assertion. |
| B. | If both assertion and reason are true but reason is not the correct explanation of the assertion. |
| C. | If assertion is true but reason is false. |
| D. | If the assertion and reason both are false. |
| Answer» E. | |