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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.
| 1001. |
A heat flux of \[4000\ J/s\] is to be passed through a copper rod of length \[10\ cm\] and area of cross-section \[100\ c{{m}^{2}}\]. The thermal conductivity of copper is \[400\ W/m{{\ }^{o}}C\]. The two ends of this rod must be kept at a temperature difference of [MP PMT 1999] |
| A. | \[{{1}^{o}}C\] |
| B. | \[{{10}^{o}}C\] |
| C. | \[{{100}^{o}}C\] |
| D. | \[{{1000}^{o}}C\] |
| Answer» D. \[{{1000}^{o}}C\] | |
| 1002. |
A solid ball of metal has a concentric spherical cavity within it. If the ball is heated, the volume of the cavity will |
| A. | Increase |
| B. | Decrease |
| C. | Remain unaffected |
| D. | None of these |
| Answer» B. Decrease | |
| 1003. |
A uniform metal rod is used as a bar pendulum. If the room temperature rises by \[10{}^\circ C\], and the coefficient of linear expansion of the metal of the rod is \[2\times {{10}^{-\,6}}\text{per}\,{}^\circ C\], the period of the pendulum will have percentage increase of |
| A. | \[-\,2\times {{10}^{-\,3}}\] |
| B. | \[-\,1\times {{10}^{-\,3}}\] |
| C. | \[2\times {{10}^{-\,3}}\] |
| D. | \[1\times {{10}^{-\,3}}\] |
| Answer» E. | |
| 1004. |
A cylindrical metal rod of length \[{{L}_{0}}\] is shaped into a ring with a small gap as shown. On heating the system |
| A. | x decreases, r and d increase |
| B. | x and r increase, d decreases |
| C. | x, r and d all increase |
| D. | Data insufficient to arrive at a conclusion |
| Answer» D. Data insufficient to arrive at a conclusion | |
| 1005. |
Four charges are arranged at the corners of a square \[ABCD\], as shown in the adjoining figure. The force on the charge kept at the centre O is [NCERT 1983; BHU 1999] |
| A. | Zero |
| B. | Along the diagonal \[AC\] |
| C. | Along the diagonal \[BD\] |
| D. | Perpendicular to side \[AB\] |
| Answer» D. Perpendicular to side \[AB\] | |
| 1006. |
A radioactive nucleus undergoes a series of decay according to the scheme \[A\xrightarrow{a}{{A}_{1}}\xrightarrow{\beta }{{A}_{2}}\xrightarrow{\alpha }{{A}_{3}}\xrightarrow{\gamma }{{A}_{4}}\] If the mass number and atomic number of 'A' are 180 and 72 respectively, then what are these numbers for \[{{A}_{4}}\] |
| A. | 172 and 69 |
| B. | 174 and 70 |
| C. | 176 and 69 |
| D. | 176 and 70 |
| Answer» B. 174 and 70 | |
| 1007. |
Putting a dielectric substance between two plates of condenser, capacity, potential and potential energy respectively [AFMC 2002] |
| A. | Increase, decrease, decrease |
| B. | Decrease, increase, increase |
| C. | Increase, increase, increase |
| D. | Decrease, decrease, decrease |
| Answer» B. Decrease, increase, increase | |
| 1008. |
One quality of a thermometer is that its heat capacity should be small. If P is a mercury thermometer, Q is a resistance thermometer and R thermocouple type then |
| A. | P is best, R worst |
| B. | R is best, P worst |
| C. | R is best, Q worst |
| D. | P is best, Q worst |
| Answer» D. P is best, Q worst | |
| 1009. |
The time period of simple pendulum of length 1m suspended in a car that is moving with constant speed 36 km/hr around a circle of radius 10mis: |
| A. | \[\pi \sqrt{2}\sec \] |
| B. | \[\frac{\pi }{10}\sqrt{2}\sec \] |
| C. | \[\frac{\pi }{10\sqrt{2}}\sec \] |
| D. | \[\frac{5\pi }{\sqrt{2}}\sec \] |
| Answer» C. \[\frac{\pi }{10\sqrt{2}}\sec \] | |
| 1010. |
A point light source S is outside a cylinder on its axis near the end face (base). Determine the minimum refractive index n of the cylinder material for which none of the rays entering the base will emerge from the lateral surface. |
| A. | \[1/\sqrt{2}~\] |
| B. | \[\sqrt{2}\] |
| C. | \[1/2~~\] |
| D. | \[~1\] |
| Answer» C. \[1/2~~\] | |
| 1011. |
A ray hits the y-axis making an angle \[\theta \] with y-axis as shown in the figure. The variation of refractive index with x-coordinate is \[\mu ={{\mu }_{0}}\left( 1-\frac{x}{d} \right)\] for \[0\le \times \le d\left( 1-\frac{1}{{{\mu }_{0}}} \right)\] and \[\mu ={{\mu }_{0}}\] for \[x |
| A. | \[d(1-\sin \theta )\] |
| B. | \[d(1-\cos \theta )\] |
| C. | \[d\,\,\sin \theta \] |
| D. | \[d\,\,\cos \theta \] |
| Answer» B. \[d(1-\cos \theta )\] | |
| 1012. |
In which of the following ionic bond is present [EAMCET (Med.) 1994] |
| A. | NaCl |
| B. | Ar |
| C. | Si |
| D. | Ge |
| Answer» B. Ar | |
| 1013. |
A capacitor is charged by using a battery which is then disconnected. A dielectric slab is then slipped between the plates, which results in [NCERT 1980; MP PET 1995; BHU 1997] |
| A. | Reduction of charge on the plates and increase of potential difference across the plates |
| B. | Increase in the potential difference across the plate, reduction in stored energy, but no change in the charge on the plates |
| C. | Decrease in the potential difference across the plates, reduction in the stored energy, but no change in the charge on the plates |
| D. | None of the above |
| Answer» D. None of the above | |
| 1014. |
Two tones of frequencies \[{{n}_{1}}\]and \[{{n}_{2}}\]are sounded together. The beats can be heard distinctly when |
| A. | \[10<({{n}_{1}}-{{n}_{2}})<20\] |
| B. | \[5<({{n}_{1}}-{{n}_{2}})>20\] |
| C. | \[5<({{n}_{1}}-{{n}_{2}})<20\] |
| D. | \[0<({{n}_{1}}-{{n}_{2}})<10\] |
| Answer» E. | |
| 1015. |
When a particle moves in a uniform circular motion. It has |
| A. | Radial velocity and radial acceleration |
| B. | Tangential velocity and radial acceleration |
| C. | Tangential velocity and tangential acceleration |
| D. | Radial velocity and tangential acceleration |
| Answer» C. Tangential velocity and tangential acceleration | |
| 1016. |
Assertion : The entropy of the solids is the highest Reason : Atoms of the solids are arranged in orderly manner. |
| 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. | |
| 1017. |
If the unit of force and length each be increased by four times, then the unit of energy is increased by [CPMT 1987] |
| A. | 16 times |
| B. | 8 times |
| C. | 2 times |
| D. | 4 times |
| Answer» B. 8 times | |
| 1018. |
A particle of mass m is moving in a circular path of constant radius r such that its centripetal acceleration \[{{a}_{c}}\] is varying with time t as \[{{a}_{c}}={{k}^{2}}r{{t}^{2}}\] where k is a constant. The power delivered to the particles by the force acting on it is |
| A. | \[2\pi m{{k}^{2}}{{r}^{2}}t\] |
| B. | \[m{{k}^{2}}{{r}^{2}}t\] |
| C. | \[\frac{\left( m{{k}^{4}}{{r}^{2}}{{t}^{5}} \right)}{3}\] |
| D. | zero |
| Answer» C. \[\frac{\left( m{{k}^{4}}{{r}^{2}}{{t}^{5}} \right)}{3}\] | |
| 1019. |
The modulus of elasticity is dimensionally equivalent to [MH CET (Med.) 1999] |
| A. | Surface tension |
| B. | Stress |
| C. | Strain |
| D. | None of these |
| Answer» C. Strain | |
| 1020. |
Assertion : Specific heat capacity is the cause of formation of land and sea breeze. Reason : The specific heat of water is more than land. [AIIMS 1995] |
| 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. | |
| 1021. |
A light wave of wavelength\[{{\lambda }_{0}}\]propagates from point A to point B. We introduce in its path a glass plate of refractive index n and thickness l. The introduction of the plate alters the phase of the plate at B by an angle\[\phi \]. If \[\lambda \] is the wavelength of lights on emerging from the plate, then |
| A. | \[\Delta \phi =0\] |
| B. | \[\Delta \phi =\frac{2\pi l}{{{\lambda }_{0}}}\] |
| C. | \[\Delta \phi =2\pi {{\ln }^{2}}\left( \frac{1}{\lambda }-\frac{1}{{{\lambda }_{0}}} \right)\] |
| D. | \[\Delta \phi =\frac{2\pi l}{{{\lambda }_{0}}}(n-1)\] |
| Answer» E. | |
| 1022. |
A coil of inductance L has an inductive reactance of \[{{X}_{L}}\] in an AC circuit in which the effective current is I. The coil is made from a super-conducting material and has no resistance. The rate at which power is dissipated in the coil is [MP PMT 1999] |
| A. | 0 |
| B. | \[I{{X}_{L}}\] |
| C. | \[{{I}^{2}}{{X}_{L}}\] |
| D. | \[IX_{L}^{2}\] |
| Answer» B. \[I{{X}_{L}}\] | |
| 1023. |
Two springs have their force constant as \[{{k}_{1}}\] and \[{{k}_{2}}({{k}_{1}}>{{k}_{2}})\]. When they are stretched by the same force [EAMCET 1981] |
| A. | No work is done in case of both the springs |
| B. | Equal work is done in case of both the springs |
| C. | More work is done in case of second spring |
| D. | More work is done in case of first spring |
| Answer» D. More work is done in case of first spring | |
| 1024. |
In a charged capacitor, the energy resides [CPMT 1974; KCET 2000] |
| A. | The positive charges |
| B. | Both the positive and negative charges |
| C. | The field between the plates |
| D. | Around the edge of the capacitor plates |
| Answer» D. Around the edge of the capacitor plates | |
| 1025. |
A body is moving in a circular path with a constant speed. It has [CPMT 1972] |
| A. | A constant velocity |
| B. | A constant acceleration |
| C. | An acceleration of constant magnitude |
| D. | An acceleration which varies with time |
| Answer» D. An acceleration which varies with time | |
| 1026. |
In an experiment with npn transistor amplifier in common emitter configuration, the current gain of the transistor is 100. If the collector current changes by \[1mA,\] what will be the change in emitter current? |
| A. | \[1.1\,mA\] |
| B. | \[1.01\,mA\] |
| C. | \[0.01\,mA\] |
| D. | \[10\,mA\] |
| Answer» C. \[0.01\,mA\] | |
| 1027. |
Assertion : Identical springs of steel and copper are equally stretched. More work will be done on the steel spring. Reason : Steel is more elastic than copper. |
| 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. | |
| 1028. |
A hollow double concave lens is made of very thin transparent material. It can be filled with air or either of two liquids \[{{L}_{1}}\] or \[{{L}_{2}}\] having refractive indices \[{{\mu }_{1}}\] and \[{{\mu }_{2}}\] respectively \[\left( {{\mu }_{2}}>{{\mu }_{1}}>1 \right)\]. The lens will diverge a parallel beam of light if it is filled with |
| A. | air and placed in air |
| B. | air and immersed in \[{{L}_{1}}\] |
| C. | \[{{L}_{1}}\] and immersed in \[{{L}_{2}}\] |
| D. | \[{{L}_{2}}\] and immersed in \[{{L}_{1}}\] |
| Answer» E. | |
| 1029. |
The coefficient of superficial expansion of a solid is 2 ´ 10?5 /°C. It's coefficient of linear expansion is [KCET 1999] |
| A. | 4 ´ 10?5/°C |
| B. | 3 ´ 10?5/°C |
| C. | 2 ´ 10?5/°C |
| D. | 1 ´ 10?5/°C |
| Answer» E. | |
| 1030. |
The ratio of the adiabatic to isothermal elasticities of a triatomic gas is [MP PET 1991] |
| A. | 3/4 |
| B. | 4/3 |
| C. | 1 |
| D. | 5/3 |
| Answer» C. 1 | |
| 1031. |
The displacement of an oscillating particle varies with time (in seconds) according to the equation y (cm) = sin \[\frac{\pi }{2}\left( \frac{t}{2}+\frac{1}{3} \right)\]. The maximum acceleration of the particle is approximately [AMU 1995] |
| A. | \[5.21cm/{{s}^{2}}\] |
| B. | \[3.62cm/{{s}^{2}}\] |
| C. | \[1.81cm/s\] |
| D. | \[0.62cm/{{s}^{2}}\] |
| Answer» E. | |
| 1032. |
A body moves with uniformly accelerated motion and travels 200 cm in the first two seconds and 220 cm in the next four seconds. What will be the velocity at the end of 7 seconds from start? |
| A. | - 10 cm/s |
| B. | 10 cm/s |
| C. | 20 cm/s |
| D. | 30 cm/s |
| Answer» C. 20 cm/s | |
| 1033. |
The engine of a motor cycle can produce maximum acceleration \[5\text{ }m/se{{c}^{2}}\]. Its breaks can produce a maximum retardation \[10\text{ }m/se{{c}^{2}}\]. What is minimum time in which it can cover a distance of 1.5 km: |
| A. | 5 sec. |
| B. | 10 sec. |
| C. | 15 sec. |
| D. | 30 sec. |
| Answer» E. | |
| 1034. |
A point mass starts moving in straight line with constant acceleration a from rest at \[t=0.\] At time \[t=2s\], the acceleration changes the sign, remaining the same in magnitude. The mass returns to the initial position at time \[t={{t}_{0}}\] after start of motion. Here \[{{t}_{0}}\] is: |
| A. | 4s |
| B. | \[(4+2\sqrt{2})s\] |
| C. | \[(2+2\sqrt{2})s\] |
| D. | \[(4+4\sqrt{2})s\] |
| Answer» C. \[(2+2\sqrt{2})s\] | |
| 1035. |
The work done in increasing the size of a soap film from 10 cm× 6 cm to 10 cm × 11 cm is 3 ×10-4 joule. The surface tension of the film is [MP PET 1999; JIPMER 2001, 02; MP PMT 2000; AIIMS 2000] |
| A. | \[1.5\times {{10}^{-2}}N/m\] |
| B. | \[3.0\times {{10}^{-2}}N/m\] |
| C. | \[6.0\times {{10}^{-2}}N/m\] |
| D. | \[11.0\times {{10}^{-2}}N/m\] |
| Answer» C. \[6.0\times {{10}^{-2}}N/m\] | |
| 1036. |
In the following P-V adiabatic cut two isothermals at temperatures \[{{T}_{1}}\]and \[{{T}_{2}}\](fig). The value of \[\frac{{{V}_{a}}}{{{V}_{c}}}\] will be |
| A. | \[\frac{{{V}_{b}}}{{{V}_{c}}}\] |
| B. | \[\frac{{{V}_{c}}}{{{V}_{b}}}\] |
| C. | \[\frac{{{V}_{d}}}{{{V}_{a}}}\] |
| D. | \[{{V}_{b}}{{V}_{c}}\] |
| Answer» B. \[\frac{{{V}_{c}}}{{{V}_{b}}}\] | |
| 1037. |
A lead bullet of 10 g travelling at 300 m/s strikes against a block of wood and comes to rest. Assuming 50% of heat is absorbed by the bullet, the increase in its temperature is (Specific heat of lead = 150J/kg, K) |
| A. | \[100{}^\circ C\] |
| B. | \[125{}^\circ C\] |
| C. | \[150{}^\circ C\] |
| D. | \[200{}^\circ C\] |
| Answer» D. \[200{}^\circ C\] | |
| 1038. |
Assertion : At critical temperature, surface tension of a liquid becomes zero. Reason : At this temperature, intermolecular forces for liquids and gases become equal. Liquid can expand without any restriction. |
| 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. | |
| 1039. |
The figure shows a pulley mass system which is kept in an elevator moving up with acceleration g. Then the tension T in the string is given by |
| A. | \[\frac{{{m}_{1}}{{m}_{2}}g}{{{m}_{1}}+{{m}_{2}}}\] |
| B. | \[\frac{2{{m}_{1}}{{m}_{2}}g}{{{m}_{1}}+{{m}_{2}}}\] |
| C. | \[\frac{4{{m}_{1}}{{m}_{2}}g}{{{m}_{1}}+{{m}_{2}}}\] |
| D. | \[\frac{({{m}_{1}}-{{m}_{2}})g}{{{m}_{1}}+{{m}_{2}}}\] |
| Answer» D. \[\frac{({{m}_{1}}-{{m}_{2}})g}{{{m}_{1}}+{{m}_{2}}}\] | |
| 1040. |
A big explosion on the moon cannot be heard on the earth because [CPMT 1972; AFMC 2005] |
| A. | The explosion produces high frequency sound waves which are inaudible |
| B. | Sound waves required a material medium for propagation |
| C. | Sound waves are absorbed in the moon's atmosphere |
| D. | Sound waves are absorbed in the earth's atmosphere |
| Answer» C. Sound waves are absorbed in the moon's atmosphere | |
| 1041. |
If a radioactive material contains 0.1 mg of \[T{{h}^{234}}\]how much of it will remain unchanged after 120 days. Given Half-life is 24 days |
| A. | \[1.12\text{ }\mu g\] |
| B. | \[0.1\text{ }\mu g\] |
| C. | \[3.125\text{ }\mu g\] |
| D. | \[125\text{ }\mu \text{g}.\] |
| Answer» D. \[125\text{ }\mu \text{g}.\] | |
| 1042. |
A tuning fork of frequency 480 Hz produces 10 beats per second when sounded with a vibrating sonometer string. What must have been the frequency of the string if a slight increase in tension produces lesser beats per second than before [NCERT 1984] |
| A. | 460 Hz |
| B. | 470 Hz |
| C. | 480 Hz |
| D. | 490 Hz |
| Answer» C. 480 Hz | |
| 1043. |
A piano convex lens fits exactly into a piano concave lens. Their plane surface are parallel to each other. If the lenses are made of different materials of refractive indices \[{{\mu }_{1}}\] & \[{{\mu }_{2}}\] and R is the radius of curvature of the curved surface of the lenses, then focal length of combination is |
| A. | \[\frac{R}{{{\mu }_{1}}-{{\mu }_{2}}}\] |
| B. | \[\frac{2R}{{{\mu }_{1}}-{{\mu }_{2}}}\] |
| C. | \[\,\frac{R}{2\left( {{\mu }_{1}}-{{\mu }_{2}} \right)}\] |
| D. | \[\,\frac{R}{2-\left( {{\mu }_{1}}+{{\mu }_{2}} \right)}\] |
| Answer» B. \[\frac{2R}{{{\mu }_{1}}-{{\mu }_{2}}}\] | |
| 1044. |
A ball of mass m moves with speed v and strikes a wall having infinite mass and it returns with same speed then the work done by the ball on the wall is [BCECE 2004] |
| A. | Zero |
| B. | \[mv\ J\] |
| C. | m/v J |
| D. | v/mJ |
| Answer» B. \[mv\ J\] | |
| 1045. |
Assertion : Bohr had to postulate that the electrons in stationary orbits around the nucleus do not radiate. Reason : According to classical physics all moving electrons radiate. [AIIMS 2003] |
| 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. | |
| 1046. |
SI unit of permittivity is [KCET 2004] |
| A. | \[{{C}^{2}}{{m}^{2}}{{N}^{-1}}\] |
| B. | \[{{C}^{-1}}{{m}^{2}}{{N}^{-2}}\] |
| C. | \[{{C}^{2}}{{m}^{2}}{{N}^{2}}\] |
| D. | \[{{C}^{2}}{{m}^{-2}}{{N}^{-1}}\] |
| Answer» E. | |
| 1047. |
In vacuum an electron of energy 10 keV hits tungsten target, then emitted radiation will be [RPMT 2001] |
| A. | Cathode rays |
| B. | X-rays |
| C. | Infrared rays |
| D. | Visible spectrum |
| Answer» C. Infrared rays | |
| 1048. |
A brass rod of cross-sectional area \[1\,c{{m}^{2}}\] and length 0.2 m is compressed lengthwise by a weight of 5 kg. If Young's modulus of elasticity of brass is \[1\times {{10}^{11}}\,N/{{m}^{2}}\] and \[g=10\,m/{{\sec }^{2}}\], then increase in the energy of the rod will be [MP PMT 1991] |
| A. | \[{{10}^{-5}}\]J |
| B. | \[2.5\times {{10}^{-5}}\]J |
| C. | \[5\times {{10}^{-5}}\]J |
| D. | \[2.5\times {{10}^{-4}}\]J |
| Answer» C. \[5\times {{10}^{-5}}\]J | |
| 1049. |
Mercury does not wet glass, wood or iron because [MP PET 1997] |
| A. | Cohesive force is less than adhesive force |
| B. | Cohesive force is greater than adhesive force |
| C. | Angle of contact is less than \[{{90}^{o}}\] |
| D. | Cohesive force is equal to adhesive force |
| Answer» C. Angle of contact is less than \[{{90}^{o}}\] | |
| 1050. |
If two vectors \[2\hat{i}\,+3\hat{j}\,+\,\hat{k}\] and \[-4\hat{i}\,-6\hat{j}\,-\lambda \hat{k}\] are parallel to each other, then value of \[\lambda \] is |
| A. | 0 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |