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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.
| 1751. |
If work W is done in blowing a bubble of radius R from a soap solution, then the work done in blowing a bubble of radius 2R from the same solution is [MP PET 1990] |
| A. | W/2 |
| B. | 2W |
| C. | 4W |
| D. | \[2\frac{1}{3}\]W |
| Answer» D. \[2\frac{1}{3}\]W | |
| 1752. |
A man walks on a straight road from his home to a market 2.5 km away with a speed of 5 km/h. Finding the market closed, he instantly turns and walks back home with a speed of 7.5 km/h. The average speed of the man over the interval of time 0 to 40 min. is equal to [AMU (Med.) 2002] |
| A. | 5 km/h |
| B. | \[\frac{25}{4}\] km/h |
| C. | \[\frac{30}{4}\] km/h |
| D. | \[\frac{45}{8}\] km/h |
| Answer» E. | |
| 1753. |
A body moving with velocity v has momentum and kinetic energy numerically equal. What is the value of v [Pb. PMT 2002; J&K CET 2004] |
| A. | 2m/s |
| B. | \[\sqrt{2}m/s\] |
| C. | 1m/s |
| D. | \[0.2\ m/s\] |
| Answer» B. \[\sqrt{2}m/s\] | |
| 1754. |
A metal ball of surface area \[200\ c{{m}^{2}}\] and temperature \[{{527}^{o}}C\] is surrounded by a vessel at \[{{27}^{o}}C\]. If the emissivity of the metal is 0.4, then the rate of loss of heat from the ball is \[(\sigma =5.67\times {{10}^{-8}}J/{{m}^{2}}\ -s-{{k}^{4}})\] |
| A. | 108 joules approx. |
| B. | 168 joules approx. |
| C. | 182 joules approx. |
| D. | 192 joules approx. |
| Answer» D. 192 joules approx. | |
| 1755. |
The radiation energy density per unit wavelength at a temperature T has a maximum at a wavelength \[{{\lambda }_{0}}\]. At temperature \[2T\], it will have a maximum at a wavelength |
| A. | 4\[{{\lambda }_{0}}\] |
| B. | 2\[{{\lambda }_{0}}\] |
| C. | \[{{\lambda }_{0}}\]/2 |
| D. | \[{{\lambda }_{0}}\]/4 |
| Answer» D. \[{{\lambda }_{0}}\]/4 | |
| 1756. |
In order to measure physical quantities in the sub-atomic world, the quantum theory often employs energy [E], angular momentum [J] and velocity [c] as fundamental dimensions instead of the usual mass, length and time. Then, the dimension of pressure in this theory is |
| A. | \[\frac{{{[E]}^{4}}}{{{[J]}^{3}}{{[c]}^{3}}}\] |
| B. | \[\frac{{{[E]}^{2}}}{[J][c]}\] |
| C. | \[\frac{[E]}{{{[J]}^{2}}{{[c]}^{2}}}\] |
| D. | \[\frac{{{[E]}^{3}}}{{{[J]}^{2}}{{[c]}^{2}}}\] |
| Answer» B. \[\frac{{{[E]}^{2}}}{[J][c]}\] | |
| 1757. |
Length of a sonometer wire between two fixed ends is 110 cm. If the fundamental frequencies are in the ratio of 1: 2: 3, then what is the ratio of lengths of these segments of the wire? |
| A. | 3 : 2 : 1 |
| B. | 6 : 3 : 2 |
| C. | 0.251423611111111 |
| D. | 0.0854861111111111 |
| Answer» C. 0.251423611111111 | |
| 1758. |
Two bodies A and B having masses in the ratio of 3 : 1 possess the same kinetic energy. The ratio of their linear momenta is then [Haryana CEE 1996] |
| A. | 3 : 1 |
| B. | 9 : 1 |
| C. | 1 : 1 |
| D. | \[\sqrt{3}:1\] |
| Answer» E. | |
| 1759. |
The depth at which the effective value of acceleration due to gravity is \[\frac{g}{4}\] is [MP PET 2003] |
| A. | R |
| B. | \[\frac{3R}{4}\] |
| C. | \[11.2\times {{10}^{2}}\,km{{s}^{-1}}\] |
| D. | \[\frac{R}{4}\] |
| Answer» C. \[11.2\times {{10}^{2}}\,km{{s}^{-1}}\] | |
| 1760. |
In a Young?s double slit experiment, the slit separation is 0.2 cm, the distance between the screen and slit is 1m. Wavelength of the light used is 5000 Å. The distance between two consecutive dark fringes (in mm) is [DCE 2004] |
| A. | 0.25 |
| B. | 0.26 |
| C. | 0.27 |
| D. | 0.28 |
| Answer» B. 0.26 | |
| 1761. |
In Young?s double slit experiment the amplitudes of two sources are 3a and a respectively. The ratio of intensities of bright and dark fringes will be [J & K CET 2004] |
| A. | 3 : 1 |
| B. | 4 : 1 |
| C. | 2 : 1 |
| D. | 9 : 1 |
| Answer» C. 2 : 1 | |
| 1762. |
In Young?s double slit experiment, distance between two sources is 0.1 mm. The distance of screen from the sources is 20 cm. Wavelength of light used is 5460 Å. Then angular position of the first dark fringe is [DCE 2002] |
| A. | 0.08° |
| B. | 0.16° |
| C. | 0.20° |
| D. | 0.313° |
| Answer» E. | |
| 1763. |
A string in musical instrument is 50 cm long and its fundamental frequency is 800 Hz. If a frequency of 1000 Hz is to be produced, then required length of string is [AIIMS 2002] |
| A. | 62.5 cm |
| B. | 50 cm |
| C. | 40 cm |
| D. | 37.5 cm |
| Answer» D. 37.5 cm | |
| 1764. |
Two wires are in unison. If the tension in one of the wires is increased by 2%, 5 beats are produced per second. The initial frequency of each wire is [MP PET 2002] |
| A. | 200 Hz |
| B. | 400 Hz |
| C. | 500 Hz |
| D. | 1000 Hz |
| Answer» D. 1000 Hz | |
| 1765. |
Two uniform strings A and B made of steel are made to vibrate under the same tension. if the first overtone of A is equal to the second overtone of B and if the radius of A is twice that of B, the ratio of the lengths of the strings is [EAMCET 2003] |
| A. | 1: 2 |
| B. | 1 : 3 |
| C. | 1 : 4 |
| D. | 1 : 6 |
| Answer» C. 1 : 4 | |
| 1766. |
Assertion : The speedometer of an automobile measure the average speed of the automobile. Reason : Average velocity is equal to total displacement per total time taken. |
| 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. | |
| 1767. |
The photoelectric threshold wavelength of a certain metal is 3000\[\overset{\text{o}}{\mathop{\text{A}}}\,\]. If the radiation of 2000\[\overset{\text{o}}{\mathop{\text{A}}}\,\] is incident on the metal |
| A. | Electrons will be emitted |
| B. | Positrons will be emitted |
| C. | Protons will be emitted |
| D. | Electrons will not be emitted |
| Answer» B. Positrons will be emitted | |
| 1768. |
Light of wavelength 4000 Å falls on a photosensitive metal and a negative 2V potential stops the emitted electrons. The work function of the material (in eV) is approximately \[(h=6.6\times {{10}^{-34}}Js,\ \ e=1.6\times {{10}^{-19}}C,\ \ c=3\times {{10}^{8}}m{{s}^{-1}})\] |
| A. | 1.1 |
| B. | 2 |
| C. | 2.2 |
| D. | 3.1 |
| Answer» B. 2 | |
| 1769. |
As the intensity of incident light increases |
| A. | Photoelectric current increases |
| B. | Photoelectric current decreases |
| C. | Kinetic energy of emitted photoelectrons increases |
| D. | Kinetic energy of emitted photoelectrons decreases |
| Answer» B. Photoelectric current decreases | |
| 1770. |
A body moves with constant angular velocity on a circle. Magnitude of angular acceleration [RPMT 2000] |
| A. | rw2 |
| B. | Constant |
| C. | Zero |
| D. | None of the above |
| Answer» D. None of the above | |
| 1771. |
The photo-electrons emitted from a surface of sodium metal are such that |
| A. | They all are of the same frequency |
| B. | They have the same kinetic energy |
| C. | They have the same de Broglie wavelength |
| D. | They have their speeds varying from zero to a certain maximum |
| Answer» E. | |
| 1772. |
The retarding potential for having zero photo-electron current |
| A. | Is proportional to the wavelength of incident light |
| B. | Increases uniformly with the increase in the wavelength of incident light |
| C. | Is proportional to the frequency of incident light |
| D. | Increases uniformly with the increase in the frequency of incident light wave |
| Answer» E. | |
| 1773. |
A radio transmitter operates at a frequency of 880 kHz and a power of 10 kW. The number of photons emitted per second are |
| A. | \[1.72\times {{10}^{31}}\] |
| B. | \[1327\times {{10}^{34}}\] |
| C. | \[13.27\times {{10}^{34}}\] |
| D. | \[0.075\times {{10}^{-34}}\] |
| Answer» B. \[1327\times {{10}^{34}}\] | |
| 1774. |
A uniform metallic object of circular shape which is free to expand in every direction is shown in figure. The parameter which will not increase on heating the object is : |
| A. | x (gap) |
| B. | r (radius of circle) |
| C. | \[\theta \] (angle formed at centre) |
| D. | t(thickness) |
| Answer» D. t(thickness) | |
| 1775. |
Mercury is poured in a U tube. Level of mercury on one side is \[{{h}_{1}}\] at temperature \[\text{5}{{\text{0}}^{\text{o}}}\text{C}\] and level of mercury on the other side is \[{{h}_{2}}\] at temperature \[\text{10}{{\text{0}}^{\text{o}}}\text{C}\] Then |
| A. | \[{{h}_{1}}={{h}_{2}}\] |
| B. | \[{{h}_{1}}<{{h}_{2}}\] |
| C. | \[{{h}_{1}}>{{h}_{2}}\] |
| D. | \[{{h}_{2}}=2{{h}_{1}}\] |
| Answer» D. \[{{h}_{2}}=2{{h}_{1}}\] | |
| 1776. |
If two rods of length L and 2L having coefficients of linear expansion \[\alpha \] and \[2\alpha \] respectively are connected so that total length becomes 3L, the average coefficient of linear expansion of the composite rod equals : |
| A. | \[\frac{3}{2}\alpha \] |
| B. | \[\frac{5}{2}\alpha \] |
| C. | \[\frac{5}{3}\alpha \] |
| D. | none of these |
| Answer» D. none of these | |
| 1777. |
A body moves due East with velocity 20 km/hour and then due North with velocity 15 km/hour. The resultant velocity [AFMC 1995] |
| A. | 5 km/hour |
| B. | 15 km/hour |
| C. | 20 km/hour |
| D. | 25 km/hour |
| Answer» E. | |
| 1778. |
A mass of 100 gm is tied to one end of a string 2 m long. The body is revolving in a horizontal circle making a maximum of 200 revolutions per min. The other end of the string is fixed at the centre of the circle of revolution. The maximum tension that the string can bear is (approximately) [MP PET 1993] |
| A. | 8.76 N |
| B. | 8.94 N |
| C. | 89.42 N |
| D. | 87.64 N |
| Answer» E. | |
| 1779. |
In an interference experiment, third bright fringe is obtained at a point on the screen with a light of 700 nm. What should be the wavelength of the light source in order to obtain 5th bright fringe at the same point [KCET 2003] |
| A. | 500 nm |
| B. | 630 nm |
| C. | 750 nm |
| D. | 420 nm |
| Answer» E. | |
| 1780. |
In a Young?s double slit experiment, the slit separation is 1 mm and the screen is 1 m from the slit. For a monochromatic light of wavelength 500 nm, the distance of 3rd minima from the central maxima is [Orissa JEE 2003] |
| A. | 0.50 mm |
| B. | 1.25 mm |
| C. | 1.50 mm |
| D. | 1.75 mm |
| Answer» C. 1.50 mm | |
| 1781. |
In Young?s double-slit experiment the fringe width is b. If entire arrangement is placed in a liquid of refractive index n, the fringe width becomes [KCET 2003] |
| A. | \[\frac{\beta }{n+1}\] |
| B. | nb |
| C. | \[\frac{\beta }{n}\] |
| D. | \[\frac{\beta }{n-1}\] |
| Answer» D. \[\frac{\beta }{n-1}\] | |
| 1782. |
A common emitter amplifier has a voltage gain of 50, an input impedance of \[100\Omega \] and an output impedance of \[200\Omega \]. The power gain of the amplifier is |
| A. | \[1000\] |
| B. | \[1250\] |
| C. | \[100\] |
| D. | \[500\] |
| Answer» C. \[100\] | |
| 1783. |
Direction: An ideal diatomic gas is confined in a cylinder A of volume \[{{V}_{0}},\] this cylinder is connected to another cylinder B with the help of tube of a negligible volume. The cylinder B is fitted with a movable piston which can be adjusted from outside. Initially, the piston is adjusted so that volume of B is the same as volume of A i.e., \[{{V}_{0}}\]. B is evacuated and the stopcork is opened so that gas expands and occupies the volume \[2{{V}_{0}}\]. [System is thermally isolated from the surroundings]. The heat absorbed by the gas is |
| A. | \[nRT\text{ }\ln \text{ }2\] |
| B. | \[-nRT\text{ }\ln \text{ }2\] |
| C. | nRT |
| D. | \[-nRT\] |
| Answer» C. nRT | |
| 1784. |
As the electron in Bohr orbit of Hydrogen atom passes from state \[n=2\] to \[n=1\], the kinetic energy K and potential energy U change as |
| A. | K two-fold, U four-fold |
| B. | K four-fold, U two-fold |
| C. | K four-fold, U also four-fold |
| D. | K two-fold, U also two-fold |
| Answer» D. K two-fold, U also two-fold | |
| 1785. |
In a cyclic process, a gas is taken from state A to B via path-I as shown in the indicator diagram and taken back to state A from state B via path-II. In the complete cycle: |
| A. | work is done by the gas |
| B. | heat is ejected by the gas |
| C. | no work is done by the gas |
| D. | nothing can be said about work as data is insufficient |
| Answer» C. no work is done by the gas | |
| 1786. |
Read the assertion and reason carefully to mark the correct option out of the options given below: Assertion : The stretching of a coil is determined by its shear modulus. Reason : Shear modulus change only shape of a body keeping its dimensions unchanged. |
| 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. | |
| 1787. |
A certain region of a soap bubble reflects red light of wavelength \[\lambda =650nm\]. What is the minimum thickness that this region of the soap bubble could have? Take the index of reflection of the soap film to be 1.41. |
| A. | \[1.2\times {{10}^{-7}}m\] |
| B. | \[650\times {{10}^{-9}}m\] |
| C. | \[120\times {{10}^{7}}m\] |
| D. | \[650\times {{10}^{5}}m\] |
| Answer» B. \[650\times {{10}^{-9}}m\] | |
| 1788. |
An infinite number of charges, each of charge 1 mC, are placed on the x-axis with co-ordinates x = 1, 2, 4, 8, ....¥. If a charge of 1 C is kept at the origin, then what is the net force acting on 1 C charge [DCE 2004] |
| A. | 9000 N |
| B. | 12000 N |
| C. | 24000 N |
| D. | 36000 N |
| Answer» C. 24000 N | |
| 1789. |
In the figure shown in a YDSE, a parallel beam of light is incident on the slits from a medium of refractive index \[{{n}_{1}}\].The wavelength of light in this medium is\[{{\lambda }_{1}}\]. A transparent slab of thickness t and refractive index is put in front of one slit. The medium between the screen and the plane of the slits is \[{{n}_{2}}\]. The phase difference between the light waves reaching point O (symmetrical, relative to the slit) is |
| A. | \[\frac{2\pi }{{{n}_{1}}{{\lambda }_{1}}}({{n}_{3}}-{{n}_{2}})t\] |
| B. | \[\frac{2\pi }{{{\lambda }_{1}}}({{n}_{3}}-{{n}_{2}})t\] |
| C. | \[\frac{2\pi {{n}_{1}}}{{{n}_{2}}{{\lambda }_{1}}}\left( \frac{{{n}_{3}}}{{{n}_{2}}}-1 \right)t\] |
| D. | \[\frac{2\pi {{n}_{1}}}{{{\lambda }_{1}}}({{n}_{3}}-{{n}_{2}})t\] |
| Answer» B. \[\frac{2\pi }{{{\lambda }_{1}}}({{n}_{3}}-{{n}_{2}})t\] | |
| 1790. |
In the figure shown the wave speed is v. The velocity of car is \[{{v}_{0}}\]. The beat frequency for the observer will be |
| A. | \[\frac{2{{f}_{0}}v{{v}_{0}}}{{{v}^{2}}+v_{0}^{2}}\] |
| B. | \[\frac{2{{f}_{0}}{{v}^{2}}}{{{v}^{2}}-v_{0}^{2}}\] |
| C. | \[\frac{2{{f}_{0}}v{{v}_{0}}}{{{v}^{2}}-{{v}_{0}}^{2}}\] |
| D. | \[\frac{{{f}_{0}}v{{v}_{0}}}{{{v}^{2}}-{{v}_{0}}^{2}}\] |
| Answer» D. \[\frac{{{f}_{0}}v{{v}_{0}}}{{{v}^{2}}-{{v}_{0}}^{2}}\] | |
| 1791. |
A pin or a needle floats on the surface of water, the reason for this is [MP PET/PMT 1988; CPMT 1975] |
| A. | Surface tension |
| B. | Less weight |
| C. | Upthrust of liquid |
| D. | None of the above |
| Answer» B. Less weight | |
| 1792. |
Assertion : It is impossible to photograph a virtual image. Reason : The rays which appear diverging from a virtual image fall on the camera and a real image is captured. |
| 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. | |
| 1793. |
Assertion : The speed of light in a rarer medium is greater than that in a denser medium Reason : One light year equals to 9.5 × 1012 km [AIIMS 1999] |
| 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. | |
| 1794. |
Assertion : Spherical aberration occur in lenses of larger aperture. Reason : The two rays, paraxial and marginal rays focus at different points. |
| 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. | |
| 1795. |
Intensity of light depends upon [RPMT 1999] |
| A. | Velocity |
| B. | Wavelength |
| C. | Amplitude |
| D. | Frequency |
| Answer» D. Frequency | |
| 1796. |
Ray diverging from a point source from a wave front that is [RPET 2000] |
| A. | Cylindrical |
| B. | Spherical |
| C. | Plane |
| D. | Cubical |
| Answer» C. Plane | |
| 1797. |
Which of the following is conserved when light waves interfere [MNR 1998] |
| A. | Intensity |
| B. | Energy |
| C. | Amplitude |
| D. | Momentum |
| Answer» C. Amplitude | |
| 1798. |
A milli voltmeter of 25 milli volt range is to be converted into an ammeter of 25 ampere range. The value (in ohm) of necessary shunt will be |
| A. | 0.001 |
| B. | 0.01 |
| C. | 1 |
| D. | 0.05 |
| Answer» B. 0.01 | |
| 1799. |
A micrometer has a resistance of\[100\Omega \] and full scale range of\[50\mu A\]. It can be used as a voltmeter or as a higher range ammeter provided a resistance is added to it. Pick the correct range and resistance combination |
| A. | 50 V range with\[10k\Omega \] resistance in series |
| B. | 10 V range with\[200k\Omega \] resistance in series |
| C. | 10 mA range with\[1\Omega \] resistance in parallel |
| D. | 10 mA range with \[0.1\Omega \] resistance in parallel |
| Answer» C. 10 mA range with\[1\Omega \] resistance in parallel | |
| 1800. |
A voltmeter has a range 0-V with a series resistance R. With a series resistance 2R, the range is\[0-V'\]. The correct relation between V and V? is |
| A. | \[V'=2V\] |
| B. | \[V'>2V\] |
| C. | \[V'>>2V\] |
| D. | \[V'<2V\] |
| Answer» E. | |