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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.
| 10551. |
A laser beam of pulse power 1012 watt is focussed on an object are 10?4 cm2. The energy flux in watt/ cm2 at the point of focus is [AFMC 2003] |
| A. | 1020 |
| B. | 1016 |
| C. | 108 |
| D. | 104 |
| Answer» C. 108 | |
| 10552. |
Assertion : Two bodies of masses M and m (M > m) are allowed to fall from the same height if the air resistance for each be the same then both the bodies will reach the earth simultaneously. Reason : For same air resistance, acceleration of both the bodies will be same. |
| 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. | |
| 10553. |
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 \[AB\] | |
| 10554. |
Assertion : Greater is the coefficient of thermal conductivity of a material, smaller is the thermal resistance of a rod of that material. Reason : Thermal resistance is the ratio of temperature difference between the ends of the conductor and rate of flow of heat. |
| 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. | |
| 10555. |
Which of the transitions in hydrogen atom emits a photon of lowest frequency (n = quantum number) [BHU 1999] |
| A. | n = 2 to n = 1 |
| B. | n = 4 to n = 3 |
| C. | n = 3 to n = 1 |
| D. | n = 4 to n = 2 |
| Answer» C. n = 3 to n = 1 | |
| 10556. |
Energy of an electron in nth orbit of hydrogen atom is \[\left( k=\frac{1}{4\pi {{\varepsilon }_{0}}} \right)\] [DCE 2002] |
| A. | \[-\frac{2{{\pi }^{2}}{{k}^{2}}m{{e}^{4}}}{{{n}^{2}}{{h}^{2}}}\] |
| B. | \[-\frac{4{{\pi }^{2}}\,m\,k{{e}^{2}}}{{{n}^{2}}{{h}^{2}}}\] |
| C. | \[-\frac{{{n}^{2}}{{h}^{2}}}{2\pi \,k\,m{{e}^{4}}}\] |
| D. | \[-\frac{{{n}^{2}}{{h}^{2}}}{4{{\pi }^{2}}\,k\,m{{e}^{2}}}\] |
| Answer» B. \[-\frac{4{{\pi }^{2}}\,m\,k{{e}^{2}}}{{{n}^{2}}{{h}^{2}}}\] | |
| 10557. |
A body is moving with a velocity v, breaks up into two equal parts. One of the part retraces back with velocity v. Then the velocity of the other part is [DCE 2004] |
| A. | v in forward direction |
| B. | 3v in forward direction |
| C. | v in backward direction |
| D. | 3v in backward direction |
| Answer» C. v in backward direction | |
| 10558. |
A bullet moving with a uniform velocity v, stops suddenly after hitting the target and the whole mass melts be m, specific heat S, initial temperature 25°C, melting point 475°C and the latent heat L. Then v is given by [NCERT 1972] |
| A. | \[mL=mS\,(475-25)+\frac{1}{2}\cdot \frac{m{{v}^{2}}}{J}\] |
| B. | \[mS(475-25)+mL=\frac{m{{v}^{2}}}{2J}\] |
| C. | \[mS\,(475-25)+mL=\frac{m{{v}^{2}}}{J}\] |
| D. | \[mS\,(475-25)-mL=\frac{m{{v}^{2}}}{2J}\] |
| Answer» C. \[mS\,(475-25)+mL=\frac{m{{v}^{2}}}{J}\] | |
| 10559. |
Two concentric coils each of radius equal to \[2\pi \text{ }cm\] are placed at right angles to each other. 3 ampere and 4 ampere are the currents flowing in each coil respectively. The magnetic induction in \[Weber/{{m}^{2}}\] at the centre of the coils will be \[({{\mu }_{0}}=4\pi \times {{10}^{-7}}Wb/A.m)\] [AIEEE 2005] |
| A. | \[5\times {{10}^{-5}}\] |
| B. | \[7\times {{10}^{-5}}\] |
| C. | \[12\times {{10}^{-5}}\] |
| D. | \[{{10}^{-5}}\] |
| Answer» B. \[7\times {{10}^{-5}}\] | |
| 10560. |
If 96500 coulombs of electricity liberates one gram equivalent of any substance, the time taken for a current of 0.15 amperes to deposite 20mg of copper from a solution of copper sulphate is (Chemical equivalent of copper = 32) [Kerala (Engg.) 2002] |
| A. | 5 min 20 sec |
| B. | 6 min 42 sec |
| C. | 4 min 40 sec |
| D. | 5 min 50 sec |
| Answer» C. 4 min 40 sec | |
| 10561. |
A charge \[Q\] is divided into two parts of \[q\] and \[Q-q\]. If the coulomb repulsion between them when they are separated is to be maximum, the ratio of \[\frac{Q}{q}\] should be [MP PET 1997] |
| A. | 2 |
| B. | \[1/2\] |
| C. | 4 |
| D. | \[1/4\] |
| Answer» B. \[1/2\] | |
| 10562. |
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 | |
| 10563. |
Assertion : The change in air pressure effect the speed of sound. Reason : The speed of sound in a gas is proportional to square root of pressure. |
| 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. | |
| 10564. |
Assertion : In everyday life the Doppler?s effect is observed readily for sound waves than light waves. Reason : Velocity of light is greater than that of sound. [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» C. If assertion is true but reason is false. | |
| 10565. |
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. | |
| 10566. |
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. | |
| 10567. |
If capillary experiment is performed in vacuum then for a liquid there [RPET 2001] |
| A. | It will rise |
| B. | Will remain same |
| C. | It will fall |
| D. | Rise to the top |
| Answer» B. Will remain same | |
| 10568. |
Assertion : The relative velocity between any two bodies moving in opposite direction is equal to sum of the velocities of two bodies. Reason : Sometimes relative velocity between two bodies is equal to difference in velocities of the two. |
| 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. | |
| 10569. |
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 | |
| 10570. |
Assertion : Water kept in an open vessel will quickly evaporate on the surface of the moon. Reason : The temperature at the surface of the moon is much higher than boiling point of the water. |
| 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. | |
| 10571. |
In a series LCR circuit, operated with an ac of angular frequency \[\omega \], the total impedance is [MP PET 1996] |
| A. | \[{{[{{R}^{2}}+{{(L\omega -C\omega )}^{2}}]}^{1/2}}\] |
| B. | \[{{\left[ {{R}^{2}}+{{\left( L\omega -\frac{1}{C\omega } \right)}^{2}} \right]}^{1/2}}\] |
| C. | \[{{\left[ {{R}^{2}}+{{\left( L\omega -\frac{1}{C\omega } \right)}^{2}} \right]}^{-1/2}}\] |
| D. | \[{{\left[ {{(R\omega )}^{2}}+{{\left( L\omega -\frac{1}{C\omega } \right)}^{2}} \right]}^{1/2}}\] |
| Answer» C. \[{{\left[ {{R}^{2}}+{{\left( L\omega -\frac{1}{C\omega } \right)}^{2}} \right]}^{-1/2}}\] | |
| 10572. |
Assertion : The binding energy of a satellite does not depend upon the mass of the satellite. Reason : Binding energy is the negative value of total energy of satellite. |
| 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. | |
| 10573. |
What is the phase difference between two successive crests in the wave [RPMT 2001, 02; MH CET 2004] |
| A. | p |
| B. | p/2 |
| C. | 2p |
| D. | 4p |
| Answer» D. 4p | |
| 10574. |
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. | |
| 10575. |
A small body of mass 0.10 kg is executing S.H.M. of amplitude 1.0 m and period 0.20 sec. The maximum force acting on it is |
| A. | 98.596 N |
| B. | 985.96 N |
| C. | 100.2 N |
| D. | 76.23 N |
| Answer» B. 985.96 N | |
| 10576. |
Assertion : Zener diode works on a principle of breakdown voltage. Reason : Current increases suddenly after breakdown voltage. |
| 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. | |
| 10577. |
Assertion : V-i characteristic of P-N junction diode is same as that of any other conductor. Reason : P-N junction diode behave as conductor at room temperature. |
| 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. | |
| 10578. |
Assertion : NOT gate is also called inverter circuit. Reason : NOT gate inverts the input order. |
| 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. | |
| 10579. |
Assertion : In circular motion, the centripetal and centrifugal force acting in opposite direction balance each other. Reason : Centripetal and centrifugal forces don?t act at the same time. |
| 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. | |
| 10580. |
When a glass rod is rubbed with silk, it [MP PET 2003] |
| A. | Gains electrons from silk |
| B. | Gives electrons to silk |
| C. | Gains protons from silk |
| D. | Gives protons to silk |
| Answer» C. Gains protons from silk | |
| 10581. |
Sixty-four drops are jointed together to form a bigger drop. If each small drop has a capacitance C, a potential V, and a charge q, then the capacitance of the bigger drop will be [AMU (Engg.) 1999] |
| A. | C |
| B. | 4C |
| C. | 16C |
| D. | 64C |
| Answer» C. 16C | |
| 10582. |
Assertion : A parallel plate capacitor is connected across battery through a key. A dielectric slab of constant K is introduced between the plates. The energy which is stored becomes K times. Reason : The surface density of charge on the plate remains constant or unchanged. [AIIMS 1996] |
| 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. | |
| 10583. |
Which of the following have highest specific charge [BHU 2005] |
| A. | Positron |
| B. | Proton |
| C. | He |
| D. | None of these |
| Answer» B. Proton | |
| 10584. |
A body of length 1m having cross sectional area 0.75m2 has heat flow through it at the rate of 6000 Joule/sec. Then find the temperature difference if \[K=200J{{m}^{-1}}{{K}^{-1}}\] [CPMT 2001] |
| A. | 20°C |
| B. | 40°C |
| C. | 80°C |
| D. | 100°C |
| Answer» C. 80°C | |
| 10585. |
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. | |
| 10586. |
If the distance between parallel plates of a capacitor is halved and dielectric constant is doubled then the capacitance [BHU 2001; CBSE PMT 2002] |
| A. | Decreases two times |
| B. | Increases two times |
| C. | Increases four times |
| D. | Remain the same |
| Answer» D. Remain the same | |
| 10587. |
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. \[I{{X}_{L}}\] | |
| 10588. |
Boiling water is changing into steam. At this stage the specific heat of water is [UPSEAT 1998] |
| A. | < 1 |
| B. | ¥ |
| C. | 1 |
| D. | 0 |
| Answer» C. 1 | |
| 10589. |
Assertion : An electron is not deflected on passing through certain region of space. This observation confirms that there is no magnetic field in that region. Reason : The deflection of electron depends on angle between velocity of electron and direction of 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» F. | |
| 10590. |
Assertion : The electric bulbs glows immediately when switch is on. Reason : The drift velocity of electrons in a metallic wire is very high. |
| 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. | |
| 10591. |
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 | |
| 10592. |
If a current I given by \[{{I}_{0}}\sin \,\left( \omega \,t-\frac{\pi }{2} \right)\] flows in an ac circuit across which an ac potential of \[E={{E}_{0}}\sin \omega \,t\] has been applied, then the power consumption P in the circuit will be [CPMT 1986; Roorkee 1992; SCRA 1996; MP PMT 1994; RPET 2001; MP PET 2001, 02] |
| A. | \[P=\frac{{{E}_{0}}{{I}_{0}}}{\sqrt{2}}\] |
| B. | \[P=\sqrt{2}{{E}_{0}}{{I}_{0}}\] |
| C. | \[P=\frac{{{E}_{0}}{{I}_{0}}}{2}\] |
| D. | P = 0 |
| Answer» E. | |
| 10593. |
Assertion : X-rays can penetrate through the flesh but not through the bones. Reason : The penetrating power of X-rays depends on voltage. |
| 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. | |
| 10594. |
0.93 watt-hour of energy is supplied to a block of ice weighing 10 gm. It is found that [NCERT 1973; DPMT 1999] |
| A. | Half of the block melts |
| B. | The entire block melts and the water attains a temperature of 4°C |
| C. | The entire block just melts |
| D. | The block remains unchanged |
| Answer» D. The block remains unchanged | |
| 10595. |
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. | |
| 10596. |
The power factor of a good choke coil is [MP PMT 1994] |
| A. | Nearly zero |
| B. | Exactly zero |
| C. | Nearly one |
| D. | Exactly one |
| Answer» B. Exactly zero | |
| 10597. |
The ionization potential for second He electron is |
| A. | 13.6 eV |
| B. | 27.2 eV |
| C. | 54.4 eV |
| D. | 100 eV |
| Answer» D. 100 eV | |
| 10598. |
The mass of a substance liberated when a charge ?q? flows through an electrolyte is proportional to [EAMCET 1984] |
| A. | q |
| B. | \[1/q\] |
| C. | \[{{q}^{2}}\] |
| D. | \[1/{{q}^{2}}\] |
| Answer» B. \[1/q\] | |
| 10599. |
Assertion : Beats can also be observed by two light sources as in sound. Reason : Light sources have constant phase deference. |
| 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. | |
| 10600. |
Assertion : Velocity of particles, while crossing mean position (in stationary waves) varies from maximum at antinodes to zero at nodes. Reason : Amplitude of vibration at antinodes is maximum and at nodes, the amplitude is zero, And all particles between two successive nodes cross the mean position together. |
| 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. | |