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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.
| 1701. |
A point source of light is placed at a distance h below the surface of a large deep lake. What is the percentage of light energy that escapes directly from the water surface if \[\mu \] of water \[=\frac{4}{3}\]? |
| A. | 0.5 |
| B. | 0.25 |
| C. | 0.2 |
| D. | 0.17 |
| Answer» E. | |
| 1702. |
Starting with a sample \[^{66}Cu,\frac{7}{8}\] of pure decays into Zn in 15 minutes. The corresponding half-life is |
| A. | 15 minutes |
| B. | 10 minutes |
| C. | \[7\frac{1}{2}\]minutes |
| D. | 5 minutes |
| Answer» E. | |
| 1703. |
Two pulses in a stretched string whose centres are initially 8 cm apart are moving towards each other as shown in the figure. The speed of each pulse is 2 cm/s. After 2 s, the total energy of the pulses will be |
| A. | Zero |
| B. | Purely kinetic |
| C. | Purely potential |
| D. | Partly kinetic and partly potential |
| Answer» C. Purely potential | |
| 1704. |
The dimensions of four wires of the same material are given below. In which wire the increase in length will be maximum when the same tension is applied [IIT 1981; NCERT 1976; MP PET/PMT 1998; CPMT 1983, 90; MP PMT 1992, 94, 97; MP PET 1989, 90, 99] |
| A. | Length 100 cm, Diameter 1 mm |
| B. | Length 200 cm, Diameter 2 mm |
| C. | Length 300 cm, Diameter 3 mm |
| D. | Length 50 cm, Diameter 0.5 mm |
| Answer» E. | |
| 1705. |
On increasing the temperature of a substance gradually, which of the following colours will be noticed by you |
| A. | White |
| B. | Yellow |
| C. | Green |
| D. | Red |
| Answer» B. Yellow | |
| 1706. |
The wavelength of maximum emitted energy of a body at 700 K is 4.08 \[\mu m\]. If the temperature of the body is raised to 1400 K, the wavelength of maximum emitted energy will be |
| A. | \[1.02\ \mu m\] |
| B. | 16.32\[\mu m\] |
| C. | 8.16\[\mu m\] |
| D. | 2.04\[\mu m\] |
| Answer» E. | |
| 1707. |
A point object is placed at a distance of 30 cm from a convex mirror of focal length 30cm. The image will form at [JIPMER 2002] |
| A. | Infinity |
| B. | Focus |
| C. | Pole |
| D. | 15 cm behind the mirror |
| Answer» E. | |
| 1708. |
The focal length of a convex mirror is 20 cm its radius of curvature will be [MP PMT 2001] |
| A. | 10 cm |
| B. | 20 cm |
| C. | 30 cm |
| D. | 40 cm |
| Answer» E. | |
| 1709. |
A concave mirror of focal length 15 cm forms an image having twice the linear dimensions of the object. The position of the object when the image is virtual will be |
| A. | 22.5 cm |
| B. | 7.5 cm |
| C. | 30 cm |
| D. | 45 cm |
| Answer» C. 30 cm | |
| 1710. |
If a body oscillates at the angular frequency \[{{\omega }_{d}}\] of the driving force, then the oscillations are called |
| A. | free oscillations |
| B. | coupled oscillations |
| C. | forced oscillations |
| D. | maintained oscillations |
| Answer» D. maintained oscillations | |
| 1711. |
A massive disc of radius R is moved with a constant velocity m on a frictionless table. Another small disc collides with it elastically with a speed of\[{{v}_{0}}= 0.3 m/s\], the velocities of the discs being parallel. The distance (/shown in the figure is equal to R/2, friction between the discs is negligible. For which u (in m/s) will the small disc move perpendicularly to its original motion after the collision? |
| A. | 0.1 |
| B. | 0.5 |
| C. | 1 |
| D. | 0.01 |
| Answer» B. 0.5 | |
| 1712. |
Two masses A and B of 10 kg and 5 kg are connected with a string passing over a frictionless pulley fixed at the corner of a table (as shown in figure). The coefficient of friction between the table and block is 0.2. The minimum mass of C that maybe placed on A to prevent it from moving is equal to |
| A. | 15 kg |
| B. | 10 kg |
| C. | 5 kg |
| D. | zero |
| Answer» B. 10 kg | |
| 1713. |
If dimensions of velocity is \[b{{c}^{-1}},\] acceleration \[b{{c}^{-2}}\] and length \[ab,\] the dimensions of coefficient of friction are |
| A. | \[{{a}^{0}}{{b}^{0}}{{c}^{0}}\] |
| B. | \[{{a}^{-1}}{{b}^{0}}{{c}^{0}}\] |
| C. | \[{{a}^{1}}{{b}^{0}}{{c}^{0}}\] |
| D. | \[{{a}^{-1}}{{b}^{-1}}{{c}^{0}}\] |
| Answer» C. \[{{a}^{1}}{{b}^{0}}{{c}^{0}}\] | |
| 1714. |
A fireman of mass 60 kg slides down a pole. He is pressing the pole with a force of 600 N. The coefficient of friction between the hands and the pole is 0.5. With what acceleration will the fireman slide down? |
| A. | \[1\,\,m/{{s}^{2}}\] |
| B. | \[2.5\,\,m/{{s}^{2}}\] |
| C. | \[10\,\,m/{{s}^{2}}\] |
| D. | \[5\,\,m/{{s}^{2}}\] |
| Answer» E. | |
| 1715. |
Two particles of equal masses are revolving in circular paths of radii \[{{r}_{1}}\] and \[{{r}_{2}}\] respectively with the same speed. The ratio of their centripetal forces is [NCERT 1984] |
| A. | \[\frac{{{r}_{2}}}{{{r}_{1}}}\] |
| B. | \[\sqrt{\frac{{{r}_{2}}}{{{r}_{1}}}}\] |
| C. | \[{{\left( \frac{{{r}_{1}}}{{{r}_{2}}} \right)}^{2}}\] |
| D. | \[{{\left( \frac{{{r}_{2}}}{{{r}_{1}}} \right)}^{2}}\] |
| Answer» B. \[\sqrt{\frac{{{r}_{2}}}{{{r}_{1}}}}\] | |
| 1716. |
The unit of \[L/R\] is (where \[L\] = inductance and \[R\] = resistance) [Orissa JEE 2002] |
| A. | \[\sec \] |
| B. | \[{{\sec }^{-1}}\] |
| C. | Volt |
| D. | Ampere |
| Answer» B. \[{{\sec }^{-1}}\] | |
| 1717. |
When a copper voltameter is connected with a battery of e.m.f. 12 volts. 2 gms of copper is deposited in 30 minutes. If the same voltameter is connected across a 6 volt battery, then the mass of copper deposited in 45 minutes would be [SCRA 1994] |
| A. | 1 gm |
| B. | 1.5 gm |
| C. | 2 gm |
| D. | 2.5 gm |
| Answer» C. 2 gm | |
| 1718. |
Two parallel glass plates are dipped partly in the liquid of density 'd' keeping them vertical. If the distance between the plates is 'x', surface tension for liquids is T and angle of contact is \[\theta \], then rise of liquid between the plates due to capillary will be [NCERT 1981] |
| A. | \[\frac{T\cos \theta }{xd}\] |
| B. | \[\frac{2T\cos \theta }{xdg}\] |
| C. | \[\frac{2T}{xdg\cos \theta }\] |
| D. | \[\frac{T\cos \theta }{xdg}\] |
| Answer» C. \[\frac{2T}{xdg\cos \theta }\] | |
| 1719. |
The amplitude of an oscillating simple pendulum is 10cm and its period is 4 sec. Its speed after 1 sec after it passes its equilibrium position, is |
| A. | Zero |
| B. | \[0.57m/s\] |
| C. | \[0.212m/s\] |
| D. | \[0.32m/s\] |
| Answer» B. \[0.57m/s\] | |
| 1720. |
A simple pendulum consisting of a ball of mass m tied to a thread of length l is made to swing on a circular arc of angle\[\theta \] in a vertical plane. At the end of this arc, another ball of mass m is placed at rest. The momentum transferred to this ball at rest by the swinging ball is [NCERT 1977] |
| A. | Zero |
| B. | \[m\theta \sqrt{\frac{g}{l}}\] |
| C. | \[\frac{m\theta }{l}\sqrt{\frac{l}{g}}\] |
| D. | \[\frac{m}{l}2\pi \sqrt{\frac{l}{g}}\] |
| Answer» B. \[m\theta \sqrt{\frac{g}{l}}\] | |
| 1721. |
The height of a swing changes during its motion from 0.1 m to 2.5 m. The minimum velocity of a boy who swings in this swing is [CPMT 1997] |
| A. | 5.4 m / s |
| B. | 4.95 m / s |
| C. | 3.14 m / s |
| D. | Zero |
| Answer» E. | |
| 1722. |
One solid sphere A and another hollow sphere B are of same mass and same outer radii. Their moments of inertia about their diameters are respectively \[{{I}_{A}}\]and \[{{I}_{B}}\] such that Here \[{{\rho }_{A}}\]and \[{{\rho }_{B}}\]represent their densities. |
| A. | \[{{I}_{A}}={{I}_{B}}\] |
| B. | \[{{I}_{A}}>{{I}_{B}}\] |
| C. | \[{{I}_{A}}<{{I}_{B}}\] |
| D. | \[{{I}_{A}}/{{I}_{B}}={{\rho }_{A}}={{\rho }_{B}}\] |
| Answer» D. \[{{I}_{A}}/{{I}_{B}}={{\rho }_{A}}={{\rho }_{B}}\] | |
| 1723. |
Assertion : All the materials always have the same colour, whether viewed by reflected light or through transmitted light. Reason : The colour of material does not depend on nature 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» E. If assertion is false but reason is true. | |
| 1724. |
Assertion : A beam of white light gives a spectrum on passing through a hollow prism. Reason : Speed of light outside the prism is different from the speed of light inside the prism. |
| 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» E. If assertion is false but reason is true. | |
| 1725. |
Assertion : By increasing the diameter of the objective of telescope, we can increase its range. Reason : The range of a telescope tells us how far away a star of some standard brightness can be spotted by telescope. |
| 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. | |
| 1726. |
The motion of a particle executing S.H.M. is given by \[x=0.01\sin 100\pi (t+.05)\], where x is in metres and time is in seconds. The time period is [CPMT 1990] |
| A. | 0.01 sec |
| B. | 0.02 sec |
| C. | 0.1 sec |
| D. | 0.2 sec |
| Answer» C. 0.1 sec | |
| 1727. |
The maximum speed of a particle executing S.H.M. is \[1m/s\] and its maximum acceleration is \[1.57m/se{{c}^{2}}\]. The time period of the particle will be [DPMT 2002] |
| A. | \[\frac{1}{1.57}sec\] |
| B. | 1.57 sec |
| C. | 2 sec |
| D. | 4 sec |
| Answer» E. | |
| 1728. |
A tunnel has been dug through the centre of the earth and a ball is released in it. It will reach the other end of the tunnel after |
| A. | 84.6 minutes |
| B. | 42.3 minutes |
| C. | 1 day |
| D. | Will not reach the other end |
| Answer» C. 1 day | |
| 1729. |
At what distance from the centre of the earth, the value of acceleration due to gravity g will be half that on the surface (R = radius of earth) [MP PMT 2001] |
| A. | 2 R |
| B. | R |
| C. | 1.414 R |
| D. | 0.414 R |
| Answer» E. | |
| 1730. |
The unit for nuclear dose given to a patient is |
| A. | Fermi |
| B. | Rutherford |
| C. | Curie |
| D. | Roentgen |
| Answer» E. | |
| 1731. |
Two waves are approaching each other with a velocity of 16 m/s and frequency n. The distance between two consecutive nodes is [CPMT 2001; Pb. PMT 1999] |
| A. | \[\frac{16}{n}\] |
| B. | \[\frac{8}{n}\] |
| C. | \[\frac{n}{16}\] |
| D. | \[\frac{n}{8}\] |
| Answer» C. \[\frac{n}{16}\] | |
| 1732. |
Two sinusoidal waves with same wavelengths and amplitudes travel in opposite directions along a string with a speed 10 ms?1. If the minimum time interval between two instants when the string is flat is 0.5 s, the wavelength of the waves is [Roorkee 2000] |
| A. | 25 m |
| B. | 20 m |
| C. | 15 m |
| D. | 10 m |
| Answer» E. | |
| 1733. |
?Stationary waves? are so called because in them [MP PMT 2001] |
| A. | The particles of the medium are not disturbed at all |
| B. | The particles of the medium do not execute SHM |
| C. | There occurs no flow of energy along the wave |
| D. | The interference effect can?t be observed |
| Answer» D. The interference effect can?t be observed | |
| 1734. |
On adjusting the P-N junction diode in forward biased [RPET 2003] |
| A. | Depletion layer increases |
| B. | Resistance increases |
| C. | Both decreases |
| D. | None of these |
| Answer» D. None of these | |
| 1735. |
A transistor can be used as an amplifier when |
| A. | emitter is forward biased and collector is reverse biased |
| B. | both are reverse biased |
| C. | both emitter and collector are forward |
| D. | None of these |
| Answer» B. both are reverse biased | |
| 1736. |
In a sonometer wire, the tension is maintained by suspending a 50.7 kg mass from the free end of the wire. The suspended mass has a volume of 0.0075 m3. The fundamental frequency of the wire is 260 Hz. If the suspended mass is completely submerged in water, the fundamental frequency will become (take g = 10 ms?2) [KCET 2001] |
| A. | 240 Hz |
| B. | 230 Hz |
| C. | 220 Hz |
| D. | 200 Hz |
| Answer» B. 230 Hz | |
| 1737. |
A string is rigidly tied at two ends and its equation of vibration is given by \[y=\cos 2\pi \,t\sin \sin \pi x.\] Then minimum length of string is [RPMT 2001] |
| A. | 1 m |
| B. | \[\frac{1}{2}m\] |
| C. | 5 m |
| D. | 2pm |
| Answer» C. 5 m | |
| 1738. |
Fundamental frequency of sonometer wire is n. If the length, tension and diameter of wire are tripled, the new fundamental frequency is [DPMT 2002] |
| A. | \[\frac{n}{\sqrt{3}}\] |
| B. | \[\frac{n}{3}\] |
| C. | \[n\sqrt{3}\] |
| D. | \[\frac{n}{3\sqrt{3}}\] |
| Answer» E. | |
| 1739. |
A plastic sheet (refractive index =1.6) covers one slit of a double slit arrangement meant for the Young's experiment. When the double slit is illuminated by monochromatic light (wavelength in air\[=6600\,\overset{o}{\mathop{A}}\,\]), the centre of the screen appears dark rather than bright. The minimum thickness of the plastic sheet to be used for this to happen is: |
| A. | \[3300\overset{o}{\mathop{A}}\,\] |
| B. | \[6600\overset{o}{\mathop{A}}\,\] |
| C. | \[2062\overset{o}{\mathop{A}}\,\] |
| D. | \[5500\overset{o}{\mathop{A}}\,\] |
| Answer» E. | |
| 1740. |
Which of the following is accompanied by the characteristic X-ray emission [MP PET 1993] |
| A. | \[\alpha -\]particle emission |
| B. | Electron emission |
| C. | Positron emission |
| D. | K?electron capture |
| Answer» E. | |
| 1741. |
Which of the following quantity is expressed as force per unit area [AFMC 1995] |
| A. | Work |
| B. | Pressure |
| C. | Volume |
| D. | Area |
| Answer» C. Volume | |
| 1742. |
Two wires are producing fundamental notes of the same frequency. Change in which of the following factors of one wire will not produce beats between them [BHU (Med.) 1999] |
| A. | Amplitude of the vibrations |
| B. | Material of the wire |
| C. | Stretching force |
| D. | Diameter of the wires |
| Answer» B. Material of the wire | |
| 1743. |
Calculate the frequency of the second harmonic formed on a string of length 0.5 m and mass 2 ´ 10?4 kg when stretched with a tension of 20 N [BHU (Med.) 2000] |
| A. | 274.4 Hz |
| B. | 744.2 Hz |
| C. | 44.72 Hz |
| D. | 447.2 Hz |
| Answer» E. | |
| 1744. |
The fundamental frequency of a string stretched with a weight of 4 kg is 256 Hz. The weight required to produce its octave is [J & K CET 2000] |
| A. | 4 kg wt |
| B. | 8 kg wt |
| C. | 12 kg wt |
| D. | 16 kg wt |
| Answer» E. | |
| 1745. |
If the angular momentum of a particle of mass m rotating along a circular path of radius r with uniform speed is L, the centripetal force acting on the particle is |
| A. | \[\frac{{{L}^{2}}}{m{{r}^{2}}}\] |
| B. | \[\frac{{{L}^{2}}}{mr}\] |
| C. | \[\frac{L}{mr}\] |
| D. | \[\frac{{{L}^{2}}m}{r}\] |
| Answer» B. \[\frac{{{L}^{2}}}{mr}\] | |
| 1746. |
The temperature on Celsius scale is 25°C. What is the corresponding temperature on the Fahrenheit scale [AFMC 2001] |
| A. | 40°F |
| B. | 77°F |
| C. | 50°F |
| D. | 45°F |
| Answer» C. 50°F | |
| 1747. |
In Young's double slit experiment intensity at a point is (1/4) of the maximum intensity. Angular position of this point is |
| A. | \[{{\sin }^{-1}}(\lambda /d)\] |
| B. | \[{{\sin }^{-1}}(\lambda /2d)\] |
| C. | \[{{\sin }^{-1}}(\lambda /3d)\] |
| D. | \[{{\sin }^{-1}}(\lambda /4d)\] |
| Answer» D. \[{{\sin }^{-1}}(\lambda /4d)\] | |
| 1748. |
In S.H. M. the ratio of kinetic energy at mean position to the potential energy when the displacement is half of the amplitude is |
| A. | \[\frac{4}{1}\] |
| B. | \[\frac{2}{3}\] |
| C. | \[\frac{4}{3}\] |
| D. | \[\frac{1}{2}\] |
| Answer» B. \[\frac{2}{3}\] | |
| 1749. |
Avalanche breakdown is due to [RPMT 2001] |
| A. | Collision of minority charge carrier |
| B. | Increase in depletion layer thickness |
| C. | Decrease in depletion layer thickness |
| D. | None of these |
| Answer» B. Increase in depletion layer thickness | |
| 1750. |
A ray of light is incident at \[50{}^\circ \] on the middle of one of the two plane mirrors arranged at an angle of \[60{}^\circ \]between them. The ray then touches the second mirror, get reflected back to the first mirror, making an angle of incidence of |
| A. | \[50{}^\circ \] |
| B. | \[60{}^\circ \] |
| C. | \[70{}^\circ \] |
| D. | \[80{}^\circ \] |
| Answer» D. \[80{}^\circ \] | |