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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.
| 451. |
Assertion : There is no effect of rotation of earth on acceleration due to gravity at poles. Reason : Rotation of earth is about polar axis. |
| 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. | |
| 452. |
If a force of 250 N act on body, the momentum acquired is 125 kg-m/s. What is the period for which force acts on the body [CMEET Bihar 1995] |
| A. | 0.5 sec |
| B. | 0.2 sec |
| C. | 0.4 sec |
| D. | 0.25 sec |
| Answer» B. 0.2 sec | |
| 453. |
A fly wheel rotating about a fixed axis has a kinetic energy of 360 joule when its angular speed is 30 radian/sec. The moment of inertia of the wheel about the axis of rotation is |
| A. | \[0.6kg/{{m}^{2}}\] |
| B. | \[0.15kg\,{{m}^{2}}\] |
| C. | \[0.8kg\,{{m}^{2}}\] |
| D. | \[0.75kg\,{{m}^{2}}\] |
| Answer» D. \[0.75kg\,{{m}^{2}}\] | |
| 454. |
The time period of a simple pendulum is 2 sec. If its length is increased 4 times, then its period becomes [CBSE PMT 1999; DPMT 1999] |
| A. | 16 sec |
| B. | 12 sec |
| C. | 8 sec |
| D. | 4 sec |
| Answer» E. | |
| 455. |
A particle \[P\] is moving in a circle of radius \['a'\] with a uniform speed \[v\]. \[C\] is the centre of the circle and \[AB\] is a diameter. When passing through B the angular velocity of \[P\] about \[A\] and \[C\] are in the ratio [NCERT 1982] |
| A. | 1 : 1 |
| B. | 1 : 2 |
| C. | 2 : 1 |
| D. | 4 : 1 |
| Answer» C. 2 : 1 | |
| 456. |
Bragg?s law for X-rays is [UPSEAT 2001] |
| A. | d sin \[\theta \]= \[2n\lambda \] |
| B. | \[2d\,\sin \,\theta =n\lambda \] |
| C. | \[n\sin \theta =2\lambda d\] |
| D. | None of these |
| Answer» C. \[n\sin \theta =2\lambda d\] | |
| 457. |
Two masses \[{{m}_{1}}\] and \[{{m}_{2}}\] are suspended together by a massless spring of constant k. When the masses are in equilibrium, \[{{m}_{1}}\] is removed without disturbing the system. Then the angular frequency of oscillation of \[{{m}_{2}}\] is |
| A. | \[\sqrt{\frac{k}{{{m}_{1}}}}\] |
| B. | \[\sqrt{\frac{k}{{{m}_{2}}}}\] |
| C. | \[\sqrt{\frac{k}{{{m}_{1}}+{{m}_{2}}}}\] |
| D. | \[\sqrt{\frac{k}{{{m}_{1}}{{m}_{2}}}}\] |
| Answer» C. \[\sqrt{\frac{k}{{{m}_{1}}+{{m}_{2}}}}\] | |
| 458. |
A vertical column 50 cm long at 50°C balances another column of same liquid 60 cm long at 100°C. The coefficient of absolute expansion of the liquid is [EAMCET 1990] |
| A. | 0.005/°C |
| B. | 0.0005/°C |
| C. | 0.002/°C |
| D. | 0.0002/°C |
| Answer» B. 0.0005/°C | |
| 459. |
A ray incident at a point at an angle of incidence of \[{{60}^{o}},\] enters a glass sphere of refractive index \[n=\sqrt{3}\] and is reflected and refracted at the further surface of the sphere. The angle between the reflected and refracted rays at this surface is |
| A. | \[50{}^\circ \] |
| B. | \[60{}^\circ \] |
| C. | \[90{}^\circ \] |
| D. | \[40{}^\circ \] |
| Answer» D. \[40{}^\circ \] | |
| 460. |
If critical angle for a material to air is 30o, the refractive index of the material will be [MP PET 2001] |
| A. | 1.0 |
| B. | 1.5 |
| C. | 2.0 |
| D. | 2.5 |
| Answer» D. 2.5 | |
| 461. |
Optical fibres are related with [AFMC 2002] |
| A. | Communication |
| B. | Light |
| C. | Computer |
| D. | None of these |
| Answer» B. Light | |
| 462. |
Assertion : In Young?s double slit experiment, the fringes become indistinct if one of the slits is covered with cellophane paper. Reason : The cellophane paper decrease the wavelength of light. |
| 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. | |
| 463. |
Assertion : Nicol prism is used to produce and analyse plane polarised light. Reason : Nicol prism reduces the intensity of light to zero. |
| 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. | |
| 464. |
Assertion : The unpolarised light and polarised light can be distinguished from each other by using polaroid. Reason : A polaroid is capable of producing plane polarised beams of light. |
| 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. | |
| 465. |
In the figure, \[{{S}_{1}}\] and \[{{S}_{2}}\] are identical springs. The oscillation frequency of the mass m is \[f\]. If one spring is removed, the frequency will become [CPMT 1971] |
| A. | \[f\] |
| B. | \[f\times 2\] |
| C. | \[f\times \sqrt{2}\] |
| D. | \[f/\sqrt{2}\] |
| Answer» E. | |
| 466. |
A mass M is suspended from a light spring. An additional mass m added displaces the spring further by a distance x. Now the combined mass will oscillate on the spring with period [CPMT 1989, 1998 ; UPSEAT 2000] |
| A. | \[T=2\pi \sqrt{\left( mg/x(M+m) \right)}\] |
| B. | \[T=2\pi \sqrt{\left( (M+m)x/mg \right)}\] |
| C. | \[T=(\pi /2)\sqrt{\left( mg/x(M+m) \right)}\] |
| D. | \[T=2\pi \sqrt{\left( (M+m)/mgx \right)}\] |
| Answer» C. \[T=(\pi /2)\sqrt{\left( mg/x(M+m) \right)}\] | |
| 467. |
The vertical extension in a light spring by a weight of 1 kg suspended from the wire is 9.8 cm. The period of oscillation [CPMT 1981; MP PMT 2003] |
| A. | \[20\pi \sec \] |
| B. | \[2\pi \sec \] |
| C. | \[2\pi /10\sec \] |
| D. | \[200\pi \sec \] |
| Answer» D. \[200\pi \sec \] | |
| 468. |
A body of mass 5 gm is executing S.H.M. about a point with amplitude 10 cm. Its maximum velocity is 100 cm/sec. Its velocity will be 50 cm/sec at a distance [CPMT 1976] |
| A. | 5 |
| B. | \[5\sqrt{2}\] |
| C. | \[5\sqrt{3}\] |
| D. | \[10\sqrt{2}\] |
| Answer» D. \[10\sqrt{2}\] | |
| 469. |
Assertion : Soft and hard X-rays differ in frequency as well as velocity. Reason : The penetrating power of hard X-rays is more than the penetrating power of soft X-rays. |
| 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. | |
| 470. |
The valence band and conduction band of a solid overlap at low temperature, the solid may be [Orissa JEE 2002; BCECE 2004] |
| A. | A metal |
| B. | A semiconductor |
| C. | An insulator |
| D. | None of these |
| Answer» B. A semiconductor | |
| 471. |
Assuming the diodes to be of silicon with for- ward resistance zero, the current I in the following circuit is |
| A. | \[0\] |
| B. | \[9.65\,mA\] |
| C. | \[10\,mA\] |
| D. | \[10.36\,mA\] |
| Answer» D. \[10.36\,mA\] | |
| 472. |
The real coefficient of volume expansion of glycerine is 0.000597 per°C and linear coefficient of expansion of glass is 0.000009 per°C. Then the apparent volume coefficient of expansion of glycerine is [AIIMS 2000] |
| A. | 0.000558 per°C |
| B. | 0.00057 per°C |
| C. | 0.00027 per°C |
| D. | 0.00066 per°C |
| Answer» C. 0.00027 per°C | |
| 473. |
Assertion : A body having non-zero acceleration can have a constant velocity. Reason : Acceleration is the rate of change of velocity. |
| 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. | |
| 474. |
If \[|\,\vec{A}+\vec{B}\,|\,=\,|\,\vec{A}\,|+|\,\vec{B}\,|\], then angle between \[\vec{A}\]and \[\vec{B}\] will be [CBSE PMT 2001] |
| A. | \[\text{9}0{}^\circ \] |
| B. | \[\text{12}0{}^\circ \] |
| C. | \[0{}^\circ \] |
| D. | \[\text{6}0{}^\circ \] |
| Answer» D. \[\text{6}0{}^\circ \] | |
| 475. |
If \[v=\frac{a}{t}+b{{t}^{3}}\] where \[v=\]velocity and t is time The dimensional formula of a and b are |
| A. | \[[T],\,[{{T}^{-3}}]\] |
| B. | \[[L],\,[L{{T}^{-4}}]\] |
| C. | \[[{{T}^{-3}}],[T]\] |
| D. | \[[L{{T}^{-4}}],[L]\] |
| Answer» C. \[[{{T}^{-3}}],[T]\] | |
| 476. |
A person sees his virtual image by holding a mirror very close to the face. When he moves the mirror away from his face, the image becomes inverted. What type of mirror he is using |
| A. | Plane mirror |
| B. | Convex mirror |
| C. | Concave mirror |
| D. | None of these |
| Answer» D. None of these | |
| 477. |
A boy stands straight infront of a mirror at a distance of \[30cm\] away from it. He sees his erect image whose height is \[\frac{1}{5}th\]of his real height. The mirror he is using is [MP PMT 1993] |
| A. | Plane mirror |
| B. | Convex mirror |
| C. | Concave mirror |
| D. | Plano-convex mirror |
| Answer» C. Concave mirror | |
| 478. |
Which one of the following statements is true |
| A. | An object situated at the principle focus of a concave lens will have its image formed at infinity |
| B. | Concave mirror can give diminished virtual image |
| C. | Given a point source of light, a convex mirror can produce a parallel beam of light |
| D. | The virtual image formed in a plane mirror can be photographed |
| Answer» E. | |
| 479. |
If the temperature of the sun becomes twice its present temperature, then |
| A. | Radiated energy would be predominantly in infrared |
| B. | Radiated energy would be predominantly in ultraviolet |
| C. | Radiated energy would be predominantly in X-ray region |
| D. | Radiated energy would become twice the present radiated energy |
| Answer» C. Radiated energy would be predominantly in X-ray region | |
| 480. |
If V be the accelerating voltage, then the maximum frequency of continuous X-rays is given by [NCERT 1971; CPMT 1991; MP PET 2000; RPMT 2001; MP PMT 2002] |
| A. | \[\frac{eh}{V}\] |
| B. | \[\frac{hV}{e}\] |
| C. | \[\frac{eV}{h}\] |
| D. | \[\frac{h}{eV}\] |
| Answer» D. \[\frac{h}{eV}\] | |
| 481. |
2 k mol of hydrogen at NTP expands isobarically to twice its initial volume. The change in its internal energy is \[({{C}_{v}}=10kJ/kg.K\]and atm pressure \[=1\times 105N/{{m}^{2}})\] |
| A. | 10.9 MJ |
| B. | 9.10 MJ |
| C. | 109 MJ |
| D. | 1.09 MJ |
| Answer» B. 9.10 MJ | |
| 482. |
In above question the energy of the characteristic X-rays given out is [IIT 1985] |
| A. | Less than 40 keV |
| B. | More than 40 keV |
| C. | Equal to 40 keV |
| D. | \[\ge \]40 keV |
| Answer» B. More than 40 keV | |
| 483. |
A nucleus decays by \[{{\beta }^{+}}\] emission followed by a gamma emission. If the atomic and mass numbers of the parent nucleus are Z and A respectively, the corresponding numbers for the daughter nucleus are respectively. |
| A. | \[Z-1\] and \[A-1\] |
| B. | \[Z+1\] and \[A\] |
| C. | \[Z-1\] and \[A\] |
| D. | \[Z+1\] and |
| Answer» D. \[Z+1\] and | |
| 484. |
What will be the final pressure if an ideal gas in a cylinder is compressed adiabatically to \[\frac{1}{3}rd\] of its volume? |
| A. | Final pressure will be three times less than initial pressure. |
| B. | Final pressure will be three times more than initial pressure. |
| C. | Change in pressure will be more than three times the initial pressure. |
| D. | Change in pressure will be less than three times the initial pressure. |
| Answer» D. Change in pressure will be less than three times the initial pressure. | |
| 485. |
In Young's experiment, the distance between the slits is reduced to half and the distance between the slit and screen is doubled, then the fringe width [IIT 1981; MP PMT 1994; RPMT 1997; KCET 2000; CPMT 2003; AMU (Engg.) 2000; DPMT 2003; UPSEAT 2000, 04; Kerala PMT 2004] |
| A. | Will not change |
| B. | Will become half |
| C. | Will be doubled |
| D. | Will become four times |
| Answer» E. | |
| 486. |
The capacity of a condenser in which a dielectric of dielectric constant 5 has been used, is \[C\]. If the dielectric is replaced by another with dielectric constant 20, the capacity will become [MP PMT 1996] |
| A. | \[\frac{C}{4}\] |
| B. | \[4C\] |
| C. | \[\frac{C}{2}\] |
| D. | \[2C\] |
| Answer» C. \[\frac{C}{2}\] | |
| 487. |
In a certain double slit experimental arrangement interference fringes of width 1.0 mm each are observed when light of wavelength 5000 Å is used. Keeping the set up unaltered, if the source is replaced by another source of wavelength 6000 Å, the fringe width will be [CPMT 1988] |
| A. | 0.5 mm |
| B. | 1.0 mm |
| C. | 1.2 mm |
| D. | 1.5 mm |
| Answer» D. 1.5 mm | |
| 488. |
In Young's double slit experiment, if the slit widths are in the ratio 1 : 9, then the ratio of the intensity at minima to that at maxima will be [MP PET 1987] |
| A. | 1 |
| B. | 1/9 |
| C. | 1/4 |
| D. | 1/3 |
| Answer» D. 1/3 | |
| 489. |
The ratio of peak value and r.m.s value of an alternating current is [MP PMT 2002] |
| A. | 1 |
| B. | \[\frac{1}{2}\] |
| C. | \[\sqrt{2}\] |
| D. | \[1/\sqrt{2}\] |
| Answer» D. \[1/\sqrt{2}\] | |
| 490. |
An object \[1cm\] tall is placed \[4cm\] infront of a mirror. In order to produce an upright image of \[3cm\] height one needs a [SCRA 1994] |
| A. | Convex mirror of radius of curvature \[12cm\] |
| B. | Concave mirror of radius of curvature \[12cm\] |
| C. | Concave mirror of radius of curvature \[4cm\] |
| D. | Plane mirror of height \[12cm\] |
| Answer» C. Concave mirror of radius of curvature \[4cm\] | |
| 491. |
A convex mirror has a focal length\[f.\] A real object is placed at a distance \[f\] in front of it from the pole produces an image at [AFMC 2005] |
| A. | Infinity |
| B. | \[f\] |
| C. | \[f/2\] |
| D. | \[2f\] |
| Answer» D. \[2f\] | |
| 492. |
Temperature of water at the surface of lake is \[-{{20}^{o}}C.\]Then temperature of water just below the lower surface of ice layer is [RPET2000] |
| A. | \[-{{4}^{o}}C\] |
| B. | \[{{0}^{o}}C\] |
| C. | \[{{4}^{o}}C\] |
| D. | \[-{{20}^{o}}C\] |
| Answer» C. \[{{4}^{o}}C\] | |
| 493. |
The energy which an \[{{e}^{-}}\] acquires when accelerated through a potential difference of 1 volt is called [UPSEAT 2000] |
| A. | 1 Joule |
| B. | 1 Electron volt |
| C. | 1 Erg |
| D. | 1 Watt. |
| Answer» C. 1 Erg | |
| 494. |
A convex lens is made up of three different materials as shown in the figure. For a point object places on its axis, the number of images formed are: |
| A. | 5 |
| B. | 1 |
| C. | 3 |
| D. | 4 |
| Answer» D. 4 | |
| 495. |
Two converging lenses are placed 20.0 cm apart. as shown in figure. If the first lens has a focal length of 10.0 cm and the second has a focal length of 20.0 cm, locate the final image formed of an object 30.0 cm in front of the first lens. |
| A. | 6.67 cm left |
| B. | 6.67 cm right |
| C. | 15.0 cm left |
| D. | 15.0 cm right |
| Answer» B. 6.67 cm right | |
| 496. |
A parallel beam of light is incident on a lens of focal length 10 cm. A parallel slab of refractive index 1.5 and thickness 3 cm is placed on the other side of the lens. The Nature of the final image from the lens slab combination is: (Assume rays paraaxial) |
| A. | At Distance of 11 cm and Image is virtual if \[X=12\text{ }cm\] |
| B. | At Distance of 11 cm and Image is virtual if \[X=14\text{ }cm\] |
| C. | At the Distance of 11 cm and Image is Virtual if \[X=16\text{ }cm\] |
| D. | All the above |
| Answer» E. | |
| 497. |
If two light waves having same frequency have intensity ratio 4 : 1 and they interfere, the ratio of maximum to minimum intensity in the pattern will be [BHU 1995; MP PMT 1995; DPMT 1999; CPMT 2003] |
| A. | 9 : 1 |
| B. | 3 : 1 |
| C. | 25 : 9 |
| D. | 16 : 25 |
| Answer» B. 3 : 1 | |
| 498. |
Two light sources are said to be coherent if they are obtained from [MP PET 1996] |
| A. | Two independent point sources emitting light of the same wavelength |
| B. | A single point source |
| C. | A wide source |
| D. | Two ordinary bulbs emitting light of different wavelengths |
| Answer» C. A wide source | |
| 499. |
Evidence for the wave nature of light cannot be obtained from [MP PET 1996] |
| A. | Reflection |
| B. | Doppler effect |
| C. | Interference |
| D. | Diffraction |
| Answer» B. Doppler effect | |
| 500. |
The impurity atom added to germanium to make it N-type semiconductor is [KCET 1993; KCET (Engg./Med.) 2000] |
| A. | Arsenic |
| B. | Iridium |
| C. | Aluminium |
| D. | Iodine |
| Answer» B. Iridium | |