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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.
| 1651. |
Which of the following is smallest unit [AFMC 1996] |
| A. | Millimetre |
| B. | Angstrom |
| C. | Fermi |
| D. | Metre |
| Answer» D. Metre | |
| 1652. |
The quantity \[\frac{PV}{KT}\] for an ideal gas represent (k = Boltzmann's constant) |
| A. | number of moles of the gas |
| B. | total mass of the gas |
| C. | number of molecules in the gas |
| D. | density of the gas |
| Answer» D. density of the gas | |
| 1653. |
Assertion : Work done by a gas in isothermal expansion is more than the work done by the gas in the same expansion, adiabatically. Reason : Temperature remains constant in isothermal expansion and not in adiabatic expansion. |
| 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. |
| E. | If assertion is false but reason is true. |
| Answer» C. If assertion is true but reason is false. | |
| 1654. |
The molecules of a given mass of gas have a \[rms\] velocity of 200 m/s at \[{{27}^{o}}C\] and \[1.0\times {{10}^{5}}\,N/{{m}^{2}}\] pressure. When the temperature is \[127{}^\circ C\] and pressure is \[0.5\times {{10}^{5}}\,N/{{m}^{2}},\] the \[rms\] velocity in m/s will be |
| A. | \[\frac{100\sqrt{2}}{3}\] |
| B. | \[100\sqrt{2}\] |
| C. | \[\frac{400}{\sqrt{3}}\] |
| D. | None of these |
| Answer» D. None of these | |
| 1655. |
Characteristic X-rays are produced due to [AIIMS 2003] |
| A. | Transfer of momentum in collision of electrons with target atoms |
| B. | Transition of electrons from higher to lower electronic orbits in an atom |
| C. | Heating of the target |
| D. | Transfer of energy in collision of electrons with atoms in the target |
| Answer» C. Heating of the target | |
| 1656. |
A source of sound gives five beats per second when sounded with another source of frequency \[100\,{{s}^{-1}}\]. The second harmonic of the source together with a source of frequency \[205\,{{s}^{-1}}\] gives five beats per second. What is the frequency of the source [CBSE PMT 1995] |
| A. | \[105\,{{s}^{-1}}\] |
| B. | \[205\,{{s}^{-1}}\] |
| C. | \[95\,{{s}^{-1}}\] |
| D. | \[100\,{{s}^{-1}}\] |
| Answer» B. \[205\,{{s}^{-1}}\] | |
| 1657. |
There is a \[5\Omega \] resistance in an ac, circuit. Inductance of 0.1H is connected with it in series. If equation of ac e.m.f. is \[5\sin 50t\] then the phase difference between current and e.m.f. is [RPET 2003] |
| A. | \[\frac{\pi }{2}\] |
| B. | \[\frac{\pi }{6}\] |
| C. | \[\frac{\pi }{4}\] |
| D. | 0 |
| Answer» D. 0 | |
| 1658. |
The meniscus of mercury in the capillary tube is [MP PET/PMT 1988] |
| A. | Convex |
| B. | Concave |
| C. | Plane |
| D. | Uncertain |
| Answer» B. Concave | |
| 1659. |
Suppose a 'n'-type wafer is creatd by doping \[Si\]crystal having \[5\times {{10}^{28}}atoms/{{m}^{3}}\] with 1 ppm concentration of As. On the surface 200 ppm Boron is added to create ?P' region in this wafer. Considering \[{{n}_{i}}=1.5\times {{10}^{6}}\,{{m}^{-3}}\] calculate the density of the minority charge carriers in the p regions. |
| A. | \[2.25\times {{10}^{7}}/{{m}^{3}}\] |
| B. | \[1.12\times {{10}^{3}}/{{m}^{3}}\] |
| C. | \[3.11\times {{10}^{6}}/{{m}^{3}}\] |
| D. | \[2.11\times {{10}^{5}}/{{m}^{3}}\] |
| Answer» B. \[1.12\times {{10}^{3}}/{{m}^{3}}\] | |
| 1660. |
The current flowing in a copper voltameter is 3.2 A. The number of copper ions \[(C{{u}^{2+}})\] deposited at the cathode per minute is [Pb. PET 2001] |
| A. | \[0.5\times {{10}^{20}}\] |
| B. | \[1.5\times {{10}^{20}}\] |
| C. | \[3\times {{10}^{20}}\] |
| D. | \[6\times {{10}^{20}}\] |
| Answer» E. | |
| 1661. |
String is massless and pulley is smooth in the adjoining figure total mass or left hand side of the pulley side of the pulley is \[{{m}_{1}}\] and on right hand side is \[{{m}_{2}}\] . Friction coefficient between block B and the wedge is \[\mu =\frac{1}{2}\] and \[\theta =30{}^\circ \] Select the wrong answer |
| A. | Block B will slide down if \[{{m}_{1}}={{m}_{2}}\] |
| B. | Block B may remain stationary with respect to wedge, for suitable values of \[{{m}_{1}}\] and \[{{m}_{2}}\] with \[{{m}_{1}}>{{m}_{2}}\] |
| C. | Block B cannot remain stationary with respect to wedge in any case |
| D. | Block B will slide down if \[{{m}_{1}}>{{m}_{2}}\] |
| Answer» C. Block B cannot remain stationary with respect to wedge in any case | |
| 1662. |
Mass of block A is 10 kg. Coefficient of friction between the block A and surface is 0.3. What is the maximum values of M for which system remains in equilibrium \[\left( g=10m/{{s}^{2}} \right)\] |
| A. | 2 kg |
| B. | 6 kg |
| C. | 3 kg |
| D. | 5 kg |
| Answer» D. 5 kg | |
| 1663. |
A simple pendulum is set into vibrations. The bob of the pendulum comes to rest after some time due to [AFMC 2003; JIPMER 1999] |
| A. | Air friction |
| B. | Moment of inertia |
| C. | Weight of the bob |
| D. | Combination of all the above |
| Answer» B. Moment of inertia | |
| 1664. |
A simple pendulum oscillates in air with time period T and amplitude A. As the time passes [CPMT 2005] |
| A. | T and A both decrease |
| B. | T increases and A is constant |
| C. | T increases and A decreases |
| D. | T decreases and A is constant |
| Answer» D. T decreases and A is constant | |
| 1665. |
A particle with restoring force proportional to displacement and resisting force proportional to velocity is subjected to a force \[F\sin \omega t\]. If the amplitude of the particle is maximum for \[\omega ={{\omega }_{1}}\] and the energy of the particle is maximum for \[\omega ={{\omega }_{2}}\], then (where w0 natural frequency of oscillation of particle) [CBSE PMT 1998] |
| A. | \[{{\omega }_{1}}={{\omega }_{0}}\] and \[{{\omega }_{2}}\ne {{\omega }_{o}}\] |
| B. | \[{{\omega }_{1}}={{\omega }_{0}}\] and \[{{\omega }_{2}}={{\omega }_{o}}\] |
| C. | \[{{\omega }_{1}}\ne {{\omega }_{0}}\] and \[{{\omega }_{2}}={{\omega }_{o}}\] |
| D. | \[{{\omega }_{1}}\ne {{\omega }_{0}}\] and \[{{\omega }_{2}}\ne {{\omega }_{o}}\] |
| Answer» D. \[{{\omega }_{1}}\ne {{\omega }_{0}}\] and \[{{\omega }_{2}}\ne {{\omega }_{o}}\] | |
| 1666. |
Length of a simple pendulum is l and its maximum angular displacement is q, then its maximum K.E. is [RPMT 1995; BHU 2003] |
| A. | \[mgl\sin \theta \] |
| B. | \[mgl(1+\sin \theta )\] |
| C. | \[mgl(1+\cos \theta )\] |
| D. | \[mgl(1-\cos \theta )\] |
| Answer» E. | |
| 1667. |
Time period of a simple pendulum will be double, if we [MH CET 2003] |
| A. | Decrease the length 2 times |
| B. | Decrease the length 4 times |
| C. | Increase the length 2 times |
| D. | Increase the length 4 times |
| Answer» D. Increase the length 4 times | |
| 1668. |
A diver looking up through the water sees the outside world contained in a circular horizon, the refractive index of water is \[\frac{4}{3}\], and the diver's eyes are 15 cm below the surface of water. Then the radius of the circle is: |
| A. | \[15\times 3\times \sqrt{5}cm\] |
| B. | \[15\times 3\sqrt{7}cm\] |
| C. | \[\frac{15\times \sqrt{7}}{3}cm\] |
| D. | \[\frac{15\times 3}{\sqrt{7}}cm\] |
| Answer» E. | |
| 1669. |
Three perfect gases at absolute temperatures \[{{T}_{1}},\,{{T}_{2}}\] and \[{{T}_{3}}\] are mixed. The masses of molecules are \[{{m}_{1}},\,{{m}_{2}}\] and \[{{m}_{3}}\] and the number of molecules are \[{{n}_{1}},\,{{n}_{2}}\] and \[{{n}_{3}},\] respectively. Assuming no loss of energy, the final temperature of the mixture is |
| A. | \[\frac{({{T}_{1}}+{{T}_{2}}+{{T}_{3}})}{3}\] |
| B. | \[\frac{{{n}_{1}}{{T}_{1}}+{{n}_{2}}{{T}_{2}}+{{n}_{3}}{{T}_{3}}}{{{n}_{1}}+{{n}_{2}}+{{n}_{3}}}\] |
| C. | \[\frac{{{n}_{1}}{{T}_{1}}+{{n}_{2}}T_{2}^{2}+{{n}_{3}}T_{3}^{2}}{{{n}_{1}}{{T}_{1}}+{{n}_{2}}{{T}_{2}}+{{n}_{3}}{{T}_{3}}}\] |
| D. | \[\frac{n_{1}^{2}T_{1}^{2}+n_{3}^{2}T_{2}^{2}+n_{3}^{2}T_{3}^{2}}{{{n}_{1}}{{T}_{1}}+{{n}_{2}}{{T}_{2}}+{{n}_{3}}{{T}_{3}}}\] |
| Answer» C. \[\frac{{{n}_{1}}{{T}_{1}}+{{n}_{2}}T_{2}^{2}+{{n}_{3}}T_{3}^{2}}{{{n}_{1}}{{T}_{1}}+{{n}_{2}}{{T}_{2}}+{{n}_{3}}{{T}_{3}}}\] | |
| 1670. |
The pressure P, volume V and temperature T of a gas in the jar A and the other gas in the jar B at pressure 2P, volume \[\frac{V}{4}\] and temperature 2T, then the ratio of, the number of molecules in the jar A and B will be |
| A. | 0.0423611111111111 |
| B. | 0.0430555555555556 |
| C. | 0.0840277777777778 |
| D. | 4 : 1 |
| Answer» E. | |
| 1671. |
Let \[\overline{v},\,{{v}_{rms}}\] and \[{{v}_{p}}\] respectively denote the mean speed, root mean square speed and most probable speed of the molecules in an ideal monoatomic gas at absolute temperature T, the mass of a molecule is m. Then |
| A. | \[{{v}_{p}}<\overline{v}<{{v}_{rms}}\] |
| B. | The average kinetic energy of a molecule is \[\frac{3}{4}mv_{p}^{2}\] |
| C. | No molecule can have speed greater than \[\sqrt{2}{{v}_{rms}}\] |
| D. | No molecule can have speed less than \[{{v}_{p}}/\sqrt{2}\] |
| Answer» C. No molecule can have speed greater than \[\sqrt{2}{{v}_{rms}}\] | |
| 1672. |
Water waves are [EAMCET 1979; AIIMS 2004] |
| A. | Longitudinal |
| B. | Transverse |
| C. | Both longitudinal and transverse |
| D. | Neither longitudinal nor transverse |
| Answer» D. Neither longitudinal nor transverse | |
| 1673. |
A system S receives heat continuously from an electrical heater of power 10 W. The temperature of S becomes constant at \[50{}^\circ C\]when the surrounding temperature is \[20{}^\circ C\]. After the heater is switched off; S cools from \[35.1{}^\circ C\] to \[34.9{}^\circ C\] in 1 minute. The heat capacity of S is |
| A. | \[100J/{}^\circ C\] |
| B. | \[300J/{}^\circ C\] |
| C. | \[750J/{}^\circ C\] |
| D. | \[1500J/{}^\circ C\] |
| Answer» E. | |
| 1674. |
After effects of elasticity are maximum for |
| A. | Glass |
| B. | Quartz |
| C. | Rubber |
| D. | Metal |
| Answer» B. Quartz | |
| 1675. |
Three rods of identical cross-sectional area and made from the same metal from the sides of an isosceles traingle ABC, right-angled at B. The points A and B are maintained at temperatures T and \[(\sqrt{2})\] T respectively. In the steady state, the temperature of the point C is \[{{T}_{c}}\]. Assuming that only heat conduction takes place, \[{{T}_{c}}/T\]is |
| A. | \[\frac{1}{2\left( \sqrt{2}-1 \right)}\] |
| B. | \[\frac{3}{\sqrt{2}+1}\] |
| C. | \[\frac{1}{\sqrt{3}\left( \sqrt{2}-1 \right)}\] |
| D. | \[\frac{1}{\sqrt{2}+1}\] |
| Answer» C. \[\frac{1}{\sqrt{3}\left( \sqrt{2}-1 \right)}\] | |
| 1676. |
If \[\Delta Q\] and \[\Delta W\] represent the heat supplied to the system and the work done on the system respectively, then the first law of thermodynamics can be written as |
| A. | \[\Delta Q=\Delta U+\Delta W\] |
| B. | \[\Delta Q=\Delta U-\Delta W\] |
| C. | \[\Delta Q=\Delta W-\Delta U\] |
| D. | \[\Delta Q=-\Delta W-\Delta U\] |
| Answer» C. \[\Delta Q=\Delta W-\Delta U\] | |
| 1677. |
A system is provided with 200 cal of heat and the work done by the system on the surrounding is 40 J. Then its internal energy |
| A. | Increases by 600 J |
| B. | Decreases by 800 J |
| C. | Increases by 800 J |
| D. | Decreases by 50 J |
| Answer» D. Decreases by 50 J | |
| 1678. |
The coefficient of self inductance of a solenoid is 0.18 mH. If a crode of soft iron of relative permeability 900 is inserted, then the coefficient of self inductance will become nearly |
| A. | 5.4 mH |
| B. | 162 mH |
| C. | 0.006 mH |
| D. | 0.0002 mH |
| Answer» C. 0.006 mH | |
| 1679. |
A piece of blue glass heated to a high temperature and a piece of red glass at room temperature, are taken inside a dimly lit room then |
| A. | The blue piece will look blue and red will look as usual |
| B. | Red look brighter red and blue look ordinary blue |
| C. | Blue shines like brighter red compared to the red piece |
| D. | Both the pieces will look equally red. |
| Answer» D. Both the pieces will look equally red. | |
| 1680. |
There is a rough black spot on a polished metallic plate. It is heated upto 1400 K approximately and then at once taken in a dark room. Which of the following statements is true |
| A. | In comparison with the plate, the spot will shine more |
| B. | In camparison with the plate, the spot will appear more black |
| C. | The spot and the plate will be equally bright |
| D. | The plate and the black spot can not be seen in the dark room |
| Answer» B. In camparison with the plate, the spot will appear more black | |
| 1681. |
In Young?s double slit experiment, the aperture screen distance is 2m. The fringe width is 1 mm. Light of 600 nm is used. If a thin plate of glass (m = 1.5) of thickness 0.06 mm is placed over one of the slits, then there will be a lateral displacement of the fringes by [BCECE 2005] |
| A. | 0 cm |
| B. | 5 cm |
| C. | 10 cm |
| D. | 15 cm |
| Answer» C. 10 cm | |
| 1682. |
In which of the following is the interference due to the division of wave front [UPSEAT 2005] |
| A. | Young's double slit experiment |
| B. | Fresnel's biprism experiment |
| C. | Lloyd's mirror experiment |
| D. | Demonstration colours of thin film |
| Answer» C. Lloyd's mirror experiment | |
| 1683. |
Two slits are separated by a distance of 0.5 mm and illuminated with light of \[\lambda =6000\]Å. If the screen is placed 2.5 m from the slits. The distance of the third bright image from the centre will be [CPMT 2005] |
| A. | 1.5 mm |
| B. | 3 mm |
| C. | 6 mm |
| D. | 9 mm |
| Answer» E. | |
| 1684. |
One-forth length of a spring of force constant K is cut away. The force constant of the remaining spring will be [MP PET 2002] |
| A. | \[\frac{3}{4}K\] |
| B. | \[\frac{4}{3}K\] |
| C. | K |
| D. | 4 K |
| Answer» C. K | |
| 1685. |
The scale of a spring balance reading from 0 to 10 kg is 0.25 m long. A body suspended from the balance oscillates vertically with a period of \[\pi /10\] second. The mass suspended is (neglect the mass of the spring) [Kerala (Engg.) 2001] |
| A. | 10 kg |
| B. | 0.98 kg |
| C. | 5 kg |
| D. | 20 kg |
| Answer» C. 5 kg | |
| 1686. |
If a spring has time period T, and is cut into n equal parts, then the time period of each part will be [AIEEE 2002] |
| A. | \[T\sqrt{n}\] |
| B. | \[T/\sqrt{n}\] |
| C. | nT |
| D. | T |
| Answer» C. nT | |
| 1687. |
Assertion : Velocity of particles, while crossing mean position (in stationary waves) varies from maximum at antinodes to zero at nodes. Reason : Amplitude of vibration at antinodes is maximum and at nodes, the amplitude is zero, And all particles between two successive nodes cross the mean position together. |
| 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. |
| E. | If assertion is false but reason is true. |
| Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion. | |
| 1688. |
Assertion : Where two vibrating tuning forks having frequencies 256 Hz and 512 Hz are held near each other, beats cannot be heard. Reason : The principle of superposition is valid only if the frequencies of the oscillators are nearly equal. |
| 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. |
| E. | If assertion is false but reason is true. |
| Answer» D. If the assertion and reason both are false. | |
| 1689. |
Assertion : The fundamental frequency of an open organ pipe increases as the temperature is increased. Reason : As the temperature increases, the velocity of sound increases more rapidly than length of the pipe. |
| 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. |
| E. | If assertion is false but reason is true. |
| Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion. | |
| 1690. |
Assertion : Aeroplanes always fly at low altitudes. Reason : According to Newton?s third law of motion, for every action there is an equal and opposite reaction. |
| 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. |
| E. | If assertion is false but reason is true. |
| Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion. | |
| 1691. |
When a beam of accelerated electrons hits a target, a continuous X-ray spectrum is emitted from the target. Which of the following wavelength is absent in the X-ray spectrum, if the X-ray tube is operating at 40,000 volts [MP PMT 1993; NCERT 1984; MNR 1995; RPMT 2002] |
| A. | 0.25 Å |
| B. | 0.5 Å |
| C. | 1.5 Å |
| D. | 1.0 Å |
| Answer» B. 0.5 Å | |
| 1692. |
An electric motor operating on a 60 V dc supply draws a current of 10 A. If the efficiency of the motor is 50%, the resistance of its winding is [AMU (Engg.) 2001] |
| A. | \[3\Omega \] |
| B. | \[6\Omega \] |
| C. | \[15\Omega \] |
| D. | \[30\Omega \] |
| Answer» B. \[6\Omega \] | |
| 1693. |
50 gm ice at 0°C in insulator vessel, 50g water of 100°C is mixed in it, then final temperature of the mixture is (neglect the heat loss) [RPMT 2001] |
| A. | 10°C |
| B. | \[0{}^\circ <<{{T}_{m}}<20{}^\circ C\] |
| C. | 20°C |
| D. | Above 20°C |
| Answer» B. \[0{}^\circ <<{{T}_{m}}<20{}^\circ C\] | |
| 1694. |
A mass M is suspended from a spring of negligible mass. The spring is pulled a little and then released so that the mass executes S.H.M. of time period T. If the mass is increased by m, the time period becomes 5T/3. Then the ratio of m/M is [AIEEE 2003] |
| A. | \[\frac{5}{3}\] |
| B. | \[\frac{3}{5}\] |
| C. | \[\frac{25}{9}\] |
| D. | \[\frac{16}{9}\] |
| Answer» E. | |
| 1695. |
A weightless spring of length 60 cm and force constant 200 N/m is kept straight and unstretched on a smooth horizontal table and its ends are rigidly fixed. A mass of 0.25 kg is attached at the middle of the spring and is slightly displaced along the length. The time period of the oscillation of the mass is [MP PET 2003] |
| A. | \[\frac{\pi }{20}s\] |
| B. | \[\frac{\pi }{10}s\] |
| C. | \[\frac{\pi }{5}s\] |
| D. | \[\frac{\pi }{\sqrt{200}}s\] |
| Answer» B. \[\frac{\pi }{10}s\] | |
| 1696. |
The time period of a mass suspended from a spring is T. If the spring is cut into four equal parts and the same mass is suspended from one of the parts, then the new time period will be [MP PMT 2002; CBSE PMT 2003] |
| A. | T |
| B. | \[\frac{T}{2}\] |
| C. | 2 T |
| D. | \[\frac{T}{4}\] |
| Answer» C. 2 T | |
| 1697. |
A uniform chain of length 2m is kept on a table such that a length of 60cm hangs freely from the edge of the table. The total mass of the chain is 4kg. What is the work done in pulling the entire chain on the table [AIEEE 2004] |
| A. | 7.2 J |
| B. | 3.6 J |
| C. | 120 J |
| D. | 1200 J |
| Answer» C. 120 J | |
| 1698. |
Assertion : The induced e.m.f. and current will be same in two identical loops of copper and aluminium, when rotated with same speed in the same magnetic field. Reason : Induced e.m.f. is proportional to rate of change of magnetic field while induced current depends on resistance of wire. |
| 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. |
| E. | If assertion is false but reason is true. |
| Answer» F. | |
| 1699. |
If unit of length and force are increased 4 times. The unit of energy |
| A. | Is increased by 4 times |
| B. | Is increased by 16 times |
| C. | Is increased by 8 times |
| D. | Remains unchanged |
| Answer» C. Is increased by 8 times | |
| 1700. |
Match List-I (Phenomenon) with List-II (Principle) and select the correct answer using the codes given below the lists List - I List - II I. Blue color of a sky A. Total internal reflection II. Glittering of diamond B. Dispersion of light III. Formation of rainbow C. Scattering of light IV. In the evening when the sun goes down blow the horizon, it continues to remain visible for some time D. Refraction of light Codes: |
| A. | I - C, II - A, III - B, IV - D |
| B. | I - C, II - A, III - D, IV - B |
| C. | I - A, II - C, III - B, IV - D |
| D. | I - A, II - C, III - D, IV - B |
| Answer» B. I - C, II - A, III - D, IV - B | |