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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.
| 8701. |
A solid sphere of mass 2 kg is resting inside a cube as shown in the figure. The cube is moving with a velocity \[v=(5t\,\hat{i}+2t\,\hat{j})m/s\]. Here t is the time in second. All surface are smooth. The sphere is at rest with respect to the cube. What is the total force exerted by the sphere on the cube. (Take g = 10 m/s2) |
| A. | \[\sqrt{29}N\] |
| B. | 29 N |
| C. | \[26\,N\] |
| D. | \[\sqrt{89}\,N\] |
| Answer» D. \[\sqrt{89}\,N\] | |
| 8702. |
A pulley fixed to the ceilling carries a string with blocks of mass m and 3 m attached to its ends. The masses of string and pulley are negligible. When the system is released, its centre of mass moves with what acceleration [UPSEAT 2002] |
| A. | 0 |
| B. | \[g/4\] |
| C. | \[g/2\] |
| D. | \[-g/2\] |
| Answer» C. \[g/2\] | |
| 8703. |
A string of negligible mass going over a clamped pulley of mass m supports a block of mass M as shown in the figure. The force on the pulley by the clamp is given by [IIT-JEE 2001] |
| A. | \[\sqrt{2}Mg\] |
| B. | \[\sqrt{2}mg\] |
| C. | \[\sqrt{{{(M+m)}^{2}}+{{m}^{2}}}g\] |
| D. | \[\sqrt{{{(M+m)}^{2}}+{{M}^{2}}}g\] |
| Answer» E. | |
| 8704. |
The pulleys and strings shown in the figure are smooth and of negligible mass. For the system to remain in equilibrium, the angle \[\theta \]should be [IIT-JEE 2001] |
| A. | \[{{0}^{o}}\] |
| B. | \[{{30}^{o}}\] |
| C. | \[{{45}^{o}}\] |
| D. | \[{{60}^{o}}\] |
| Answer» D. \[{{60}^{o}}\] | |
| 8705. |
In the arrangement shown in figure the ends P and Q of an unstretchable string move downwards with uniform speed U. Pulleys A and B are fixed. Mass M moves upwards with a speed [IIT 1982] |
| A. | \[2U\cos \theta \] |
| B. | \[U\cos \theta \] |
| C. | \[\frac{2U}{\cos \theta }\] |
| D. | \[\frac{U}{\cos \theta }\] |
| Answer» E. | |
| 8706. |
A small block slides without friction down an inclined plane starting from rest. Let \[{{S}_{n}}\]be the distance travelled from time \[t=n-1\] to \[t=n.\] Then \[\frac{{{S}_{n}}}{{{S}_{n+1}}}\] is [IIT-JEE (Screening) 2004] |
| A. | \[\frac{2n-1}{2n}\] |
| B. | \[\frac{2n+1}{2n-1}\] |
| C. | \[\frac{2n-1}{2n+1}\] |
| D. | \[\frac{2n}{2n+1}\] |
| Answer» D. \[\frac{2n}{2n+1}\] | |
| 8707. |
An insect crawls up a hemispherical surface very slowly (see the figure). The coefficient of friction between the insect and the surface is 1/3. If the line joining the centre of the hemispherical surface to the insect makes an angle \[\alpha \]with the vertical, the maximum possible value of \[\alpha \] is given by [IIT-JEE 2001] |
| A. | \[\cot \alpha =3\] |
| B. | \[\tan \alpha =3\] |
| C. | \[\sec \alpha =3\] |
| D. | \[\text{cosec}\,\alpha =\text{3}\] |
| Answer» B. \[\tan \alpha =3\] | |
| 8708. |
The vector sum of two forces is perpendicular to their vector differences. In that case, the force [CBSE PMT 2003] |
| A. | Are equal to each other in magnitude |
| B. | Are not equal to each other in magnitude |
| C. | Cannot be predicted |
| D. | Are equal to each other |
| Answer» B. Are not equal to each other in magnitude | |
| 8709. |
When a bicycle is in motion, the force of friction exerted by the ground on the two wheels is such that it acts [IIT 1990; Manipal MEE 1995; MP PET 1996] |
| A. | In the backward direction on the front wheel and in the forward direction on the rear wheel |
| B. | In the forward direction on the front wheel and in the backward direction on the rear wheel |
| C. | In the backward direction on both front and the rear wheels |
| D. | In the forward direction on both front and the rear wheels |
| Answer» B. In the forward direction on the front wheel and in the backward direction on the rear wheel | |
| 8710. |
A false balance has equal arms. An object weigh X when placed in one pan and Y when placed in other pan, then the weight W of the object is equal to [AFMC 1994] |
| A. | \[\sqrt{XY}\] |
| B. | \[\frac{X+Y}{2}\] |
| C. | \[\frac{{{X}^{2}}+{{Y}^{2}}}{2}\] |
| D. | \[\frac{2}{\sqrt{{{X}^{2}}+{{Y}^{2}}}}\] |
| Answer» C. \[\frac{{{X}^{2}}+{{Y}^{2}}}{2}\] | |
| 8711. |
A man throws balls with the same speed vertically upwards one after the other at an interval of 2 seconds. What should be the speed of the throw so that more than two balls are in the sky at any time (Given \[g=9.8m/{{s}^{2}})\] [CBSE PMT 2003] |
| A. | At least 0.8 m/s |
| B. | Any speed less than 19.6 m/s |
| C. | Only with speed 19.6 m/s |
| D. | More than 19.6 m/s |
| Answer» E. | |
| 8712. |
A vessel containing water is given a constant acceleration a towards the right, along a straight horizontal path. Which of the following diagram represents the surface of the liquid [IIT 1981] |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 8713. |
A block of mass m lying on a rough horizontal plane is acted upon by a horizontal force P and another force Q inclined at an angle \[\theta \] to the vertical. The block will remain in equilibrium, if the coefficient of friction between it and the surface is [Haryana CEE 1996] |
| A. | \[\frac{(P+Q\sin \theta )}{(mg+Q\cos \theta )}\] |
| B. | \[\frac{(P\cos \theta +Q)}{(mg-Q\sin \theta )}\] |
| C. | \[\frac{(P+Q\cos \theta )}{(mg+Q\sin \theta )}\] |
| D. | \[\frac{(P\sin \theta -Q)}{(mg-Q\cos \theta )}\] |
| Answer» B. \[\frac{(P\cos \theta +Q)}{(mg-Q\sin \theta )}\] | |
| 8714. |
A particle moving in a straight line covers half the distance with speed of 3 m/s. The other half of the distance is covered in two equal time intervals with speed of 4.5 m/s and 7.5 m/s respectively. The average speed of the particle during this motion is [IIT 1992] |
| A. | 4.0 m/s |
| B. | 5.0 m/s |
| C. | 5.5 m/s |
| D. | 4.8 m/s |
| Answer» B. 5.0 m/s | |
| 8715. |
In heat transfer, which method is based on gravitation [CBSE PMT 2000] |
| A. | Natural convection |
| B. | Conduction |
| C. | Radiation |
| D. | Stirring of liquids |
| Answer» B. Conduction | |
| 8716. |
In a closed room, heat transfer takes place by [BHU 2001] |
| A. | Conduction |
| B. | Convection |
| C. | Radiation |
| D. | All of these |
| Answer» C. Radiation | |
| 8717. |
Mode of transmission of heat, in which heat is carried by the moving particles, is [KCET 1999] |
| A. | Radiation |
| B. | Conduction |
| C. | Convection |
| D. | Wave motion |
| Answer» D. Wave motion | |
| 8718. |
While measuring the thermal conductivity of a liquid, we keep the upper part hot and lower part cool, so that [CPMT 1985; MP PMT/PET 1988] |
| A. | Convection may be stopped |
| B. | Radiation may be stopped |
| C. | Heat conduction is easier downwards |
| D. | It is easier and more convenient to do so |
| Answer» B. Radiation may be stopped | |
| 8719. |
One likes to sit under sunshine in winter season, because |
| A. | The air surrounding the body is hot by which body gets heat |
| B. | We get energy by sun |
| C. | We get heat by conduction by sun |
| D. | None of the above |
| Answer» B. We get energy by sun | |
| 8720. |
In which of the following process, convection does not take place primarily [IIT-JEE (Screening) 2005] |
| A. | Sea and land breeze |
| B. | Boiling of water |
| C. | Warming of glass of bulb due to filament |
| D. | Heating air around a furnace |
| Answer» D. Heating air around a furnace | |
| 8721. |
The rate of loss of heat from a body cooling under conditions of forced convection is proportional to its heat capacity surface area absolute temperature excess of temperature over that of surrounding : state if [NCERT 1982] |
| A. | A, B, C are correct |
| B. | Only A and C are correct |
| C. | Only B and D are correct |
| D. | Only D is correct |
| Answer» D. Only D is correct | |
| 8722. |
It is hotter for the same distance over the top of a fire than it is in the side of it, mainly because [NCERT 1976, 79, 80; AIIMS 2000] |
| A. | Air conducts heat upwards |
| B. | Heat is radiated upwards |
| C. | Convection takes more heat upwards |
| D. | Convection, conduction and radiation all contribute significantly transferring heat upwards |
| Answer» D. Convection, conduction and radiation all contribute significantly transferring heat upwards | |
| 8723. |
When fluids are heated from the bottom, convection currents are produced because [UPSEAT 2000] |
| A. | Molecular motion of fluid becomes aligned |
| B. | Molecular collisions take place within the fluid |
| C. | Heated fluid becomes more dense than the cold fluid above it |
| D. | Heated fluid becomes less dense than the cold fluid above it |
| Answer» E. | |
| 8724. |
The spectral series of the hydrogen spectrum that lies in the ultraviolet region is the [CPMT 1990; MP PET 1994; MP PMT 2000] |
| A. | Balmer series |
| B. | Pfund series |
| C. | Paschen series |
| D. | Lyman series |
| Answer» E. | |
| 8725. |
Assuming earth to be a sphere of a uniform density, what is the value of gravitational acceleration in a mine 100 km below the earth?s surface (Given R = 6400 km) [AFMC 2000; Pb. PMT 2000] |
| A. | \[9.66\,m/{{s}^{2}}\] |
| B. | \[7.64\,m/{{s}^{2}}\] |
| C. | \[5.06m/{{s}^{2}}\] |
| D. | \[3.10\,m/{{s}^{2}}\] |
| Answer» B. \[7.64\,m/{{s}^{2}}\] | |
| 8726. |
For a particle executing simple harmonic motion, which of the following statements is not correct [MP PMT 1997; AIIMS 1999; Kerala PMT 2005] |
| A. | The total energy of the particle always remains the same |
| B. | The restoring force of always directed towards a fixed point |
| C. | The restoring force is maximum at the extreme positions |
| D. | The acceleration of the particle is maximum at the equilibrium position |
| Answer» E. | |
| 8727. |
The angular momentum of electron in nth orbit is given by [Roorkee 1993] |
| A. | nh |
| B. | \[\frac{h}{2\pi n}\] |
| C. | \[n\frac{h}{2\pi }\] |
| D. | \[{{n}^{2}}\frac{h}{2\pi }\] |
| Answer» D. \[{{n}^{2}}\frac{h}{2\pi }\] | |
| 8728. |
Water is used to cool radiators of engines, because [AFMC 2001] |
| A. | Of its lower density |
| B. | It is easily available |
| C. | It is cheap |
| D. | It has high specific heat |
| Answer» E. | |
| 8729. |
Two rods of same length and cross section are joined along the length. Thermal conductivities of first and second rod are \[{{K}_{1}}\,\,\text{and}\,\,{{K}_{2}}\]. The temperature of the free ends of the first and second rods are maintained at \[{{\theta }_{1}}\,\,\text{and }{{\theta }_{2}}\] respectively. The temperature of the common junction is [MP PET 2003] |
| A. | \[\frac{{{\theta }_{1}}+{{\theta }_{2}}}{2}\] |
| B. | \[\frac{{{K}_{2}}{{K}_{2}}}{{{K}_{1}}+{{K}_{2}}}({{\theta }_{1}}+{{\theta }_{2}})\] |
| C. | \[\frac{{{K}_{1}}{{\theta }_{1}}+{{K}_{2}}{{\theta }_{2}}}{{{K}_{1}}+{{K}_{2}}}\] |
| D. | \[\frac{{{K}_{2}}{{\theta }_{1}}+{{K}_{1}}{{\theta }_{2}}}{{{K}_{1}}+{{K}_{2}}}\] |
| Answer» D. \[\frac{{{K}_{2}}{{\theta }_{1}}+{{K}_{1}}{{\theta }_{2}}}{{{K}_{1}}+{{K}_{2}}}\] | |
| 8730. |
Which one of the relation is correct between time period and number of orbits while an electron is revolving in a orbit [DPMT 2003] |
| A. | \[{{n}^{2}}\] |
| B. | \[\frac{1}{{{n}^{2}}}\] |
| C. | \[{{n}^{3}}\] |
| D. | \[\frac{1}{n}\] |
| Answer» D. \[\frac{1}{n}\] | |
| 8731. |
The capacitance of a metallic sphere will be\[1\mu F\], if its radius is nearly [MP PMT 1992; MH CET (Med.) 2001; UPSEAT 1999] |
| A. | 9 \[km\] |
| B. | 10\[m\] |
| C. | 1.11 \[m\] |
| D. | 1.11 \[cm\] |
| Answer» B. 10\[m\] | |
| 8732. |
In terms of Rydberg's constant R, the wave number of the first Balmer line is [MP PMT 1996] |
| A. | R |
| B. | 3R |
| C. | \[\frac{5R}{36}\] |
| D. | \[\frac{8R}{9}\] |
| Answer» D. \[\frac{8R}{9}\] | |
| 8733. |
Assertion : Two persons on the surface of moon cannot talk to each other. Reason : There is no atmosphere on moon. |
| 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. | |
| 8734. |
\[{{O}^{++}},\ {{C}^{+}},\ H{{e}^{++}}\] and \[{{H}^{+}}\] ions are projected on the photographic plate with same velocity in a mass spectrograph. Which one will strike farthest [RPMT 2003] |
| A. | \[{{O}^{++}}\] |
| B. | \[{{C}^{+}}\] |
| C. | \[H{{e}^{++}}\] |
| D. | \[H_{2}^{+}\] |
| Answer» C. \[H{{e}^{++}}\] | |
| 8735. |
In order that the heat flows from one part of a solid to another part, what is required [Pb. PMT 1999; EAMCET 1998] |
| A. | Uniform density |
| B. | Density gradient |
| C. | Temperature gradient |
| D. | Uniform temperature |
| Answer» D. Uniform temperature | |
| 8736. |
Assertion : Magnetic flux can produce induced e.m.f. Reason : Faraday established induced e.m.f. experimentally. |
| 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. | |
| 8737. |
The correct answer to above question is based on [NCERT 1975] |
| A. | Acceleration due to gravity in vacuum is same irrespective of size and mass of the body |
| B. | Acceleration due to gravity in vacuum depends on the mass of the body |
| C. | There is no acceleration due to gravity in vacuum |
| D. | In vacuum there is resistance offered to the motion of the body and this resistance depends on the mass of the body |
| Answer» B. Acceleration due to gravity in vacuum depends on the mass of the body | |
| 8738. |
A parallel plate capacitor of capacity \[{{C}_{0}}\] is charged to a potential \[{{V}_{0}}\] (i) The energy stored in the capacitor when the battery is disconnected and the separation is doubled \[{{E}_{1}}\] (ii) The energy stored in the capacitor when the charging battery is kept connected and the separation between the capacitor plates is doubled is \[{{E}_{2}}.\] Then \[{{E}_{1}}/{{E}_{2}}\] value is [EAMCET 2003] |
| A. | 4 |
| B. | 3/2 |
| C. | 2 |
| D. | 1/2 |
| Answer» B. 3/2 | |
| 8739. |
Assertion : The refractive index of a prism depends only on the kind of glass of which it is made of and the colour of light Reason : The refractive index of a prism depends upon the refracting angle of the prism and the angle of minimum deviation [AIIMS 2000] |
| 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. | |
| 8740. |
Assertion : The resolving power of a telescope is more if the diameter of the objective lens is more. Reason : Objective lens of large diameter collects more light. [AIIMS 2005] |
| 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. | |
| 8741. |
Assertion : By roughening the surface of a glass sheet its transparency can be reduced. Reason : Glass sheet with rough surface absorbs more light. [AIIMS 2005] |
| 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. | |
| 8742. |
In Bohr?s model of hydrogen atom, which of the following pairs of quantities are quantized [UPSEAT 2004] |
| A. | Energy and linear momentum |
| B. | Linear and angular momentum |
| C. | Energy and angular momentum |
| D. | None of the above |
| Answer» D. None of the above | |
| 8743. |
Assertion : To protect any instrument from external magnetic field, it is put inside an iron body. Reason : Iron is a magnetic substance. |
| 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. | |
| 8744. |
When cathode rays (tube voltage ~ 10 kV) collide with the anode of high atomic weight then we get [MP PET 1985] |
| A. | Positive rays |
| B. | X-rays |
| C. | Gamma rays |
| D. | Canal rays |
| Answer» C. Gamma rays | |
| 8745. |
Assertion : Under given conditions of pressure and temperature, sound travels faster in a monoatomic gas than in diatomic gas. Reason : Opposition for wave to travel is more in diatomic gas than monoatomic gas. |
| 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. | |
| 8746. |
Assertion : The speed of sound in solids is maximum though their density is large. Reason : The coefficient of elasticity of solid is large. |
| 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. | |
| 8747. |
If in nature there may not be an element for which the principal quantum number n > 4, then the total possible number of elements will be [IIT 1983; MP PET 1999; RPMT 1999; RPET 2001] |
| A. | 60 |
| B. | 32 |
| C. | 4 |
| D. | 64 |
| Answer» B. 32 | |
| 8748. |
Two capillaries made of the same material with radii \[{{r}_{1}}=1mm\] and \[{{r}_{2}}=2mm\]. The rise of the liquid in one capillary (\[{{r}_{1}}=mm\]) is 30 cm, then the rise in the other will be [MP PET 1991] |
| A. | 7.5 cm |
| B. | 60 cm |
| C. | 15 cm |
| D. | 120 cm |
| Answer» D. 120 cm | |
| 8749. |
For sky wave propagation of a 10 MHz signal, what should be the minimum electron density in ionosphere [AIIMS 2005] |
| A. | ~ 1.2 ´ 1012 m?3 |
| B. | ~ 106 m?3 |
| C. | ~ 1014 m?3 |
| D. | ~ 1022 m?3 |
| Answer» B. ~ 106 m?3 | |
| 8750. |
Assertion : Magnetic moment of an atom is due to both, the orbital motion and spin motion of every electron. Reason : A charged particle produces a magnetic field. |
| 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. | |