MCQOPTIONS
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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.
| 9551. |
Energy of electrons can be increased by allowing them [JIPMER 1997] |
| A. | To fall through electric potential |
| B. | To move in high magnetic field |
| C. | To fall from great heights |
| D. | To pass through lead blocks |
| Answer» B. To move in high magnetic field | |
| 9552. |
An isolated solid metallic sphere is given \[+Q\] charge. The charge will be distributed on the sphere [MP PET 1987] |
| A. | Uniformly but only on surface |
| B. | Only on surface but non-uniformly |
| C. | Uniformly inside the volume |
| D. | Non-uniformly inside the volume |
| Answer» B. Only on surface but non-uniformly | |
| 9553. |
Assertion : Penetrating power of X-rays increases with the increasing the wavelength. Reason : The penetrating power of X-rays increases with the frequency of X-rays. |
| 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. | |
| 9554. |
Two thin blankets keep more hotness than one blanket of thickness equal to these two. The reason is |
| A. | Their surface area increases |
| B. | A layer of air is formed between these two blankets, which is bad conductor |
| C. | These have more wool |
| D. | They absorb more heat from outside |
| Answer» C. These have more wool | |
| 9555. |
The reactance of a coil when used in the domestic ac power supply (220 volts, 50 cycles per second) is 50 ohms. The inductance of the coil is nearly [MP PMT 2000] |
| A. | 2.2 henry |
| B. | 0.22 henry |
| C. | 1.6 henry |
| D. | 0.16 henry |
| Answer» C. 1.6 henry | |
| 9556. |
Woollen clothes are used in winter season because woolen clothes [EAMCET 1978; AIIMS 1998] |
| A. | Are good sources for producing heat |
| B. | Absorb heat from surroundings |
| C. | Are bad conductors of heat |
| D. | Provide heat to body continuously |
| Answer» D. Provide heat to body continuously | |
| 9557. |
Assertion : Air quickly leaking out of a balloon becomes coolers Reason : The leaking air undergoes adiabatic expansion. [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. | |
| 9558. |
From the following, what charges can be present on oil drops in Millikan's experiment [MP PET 1995] |
| A. | Zero, equal to the magnitude of charge on \[\alpha -\]particle |
| B. | \[2e,\ 1.6\times {{10}^{-18}}C,\] |
| C. | \[1.6\times {{10}^{-19}}C,\ 2.5e\] |
| D. | \[1.5e,\ e\] (Here e is the electronic charge) |
| Answer» C. \[1.6\times {{10}^{-19}}C,\ 2.5e\] | |
| 9559. |
Assertion : Temperatures near the sea coast are moderate. Reason : Water has a high thermal conductivity. [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. | |
| 9560. |
Cathode rays are produced when the pressure is of the order of [Kerala (Engg.) 2002] |
| A. | 2 cm of Hg |
| B. | 0.1 cm of Hg |
| C. | 0.01 mm of Hg |
| D. | 1 \[\mu m\] of Hg |
| Answer» D. 1 \[\mu m\] of Hg | |
| 9561. |
The phenomenon by which light travels in an optical fibres is [DCE 2001] |
| A. | Reflection |
| B. | Refraction |
| C. | Total internal reflection |
| D. | Transmission |
| Answer» D. Transmission | |
| 9562. |
Assertion : Force is required to move a body uniformly along a circle. Reason : When the motion is uniform, acceleration is 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» C. If assertion is true but reason is false. | |
| 9563. |
Which of the following is the disadvantage of FM over AM |
| A. | Larger band width requirement |
| B. | Larger noise |
| C. | Higher modulation power |
| D. | Low efficiency |
| Answer» B. Larger noise | |
| 9564. |
Assertion : Dielectric breakdown occurs under the influence of an intense light beam. Reason : Electromagnetic radiations exert 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» C. If assertion is true but reason is false. | |
| 9565. |
Assertion : For a perfectly diamagnetic substance permeability is always one. Reason : The ability of a material of permit the passage of magnetic lines of force through it is called magnetic permeability. |
| 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. | |
| 9566. |
The ratio of the coefficient of thermal conductivity of two different materials is 5 : 3. If the thermal resistance of the rod of same thickness resistance of the rods of same thickness of these materials is same, then the ratio of the length of these rods will be [BHU 2000] |
| A. | 3 : 5 |
| B. | 5 : 3 |
| C. | 3 : 4 |
| D. | 3 : 2 |
| Answer» C. 3 : 4 | |
| 9567. |
Two point charges placed at a certain distance r in air exert a force F on each other. Then the distance r' at which these charges will exert the same force in a medium of dielectric constant k is given by [EAMCET 1990; MP PMT 2001] |
| A. | r |
| B. | r/k |
| C. | \[r/\sqrt{k}\] |
| D. | \[r\sqrt{k}\] |
| Answer» D. \[r\sqrt{k}\] | |
| 9568. |
The splitting of line into groups under the effect of electric or magnetic field is called [AFMC 1995] |
| A. | Zeeman's effect |
| B. | Bohr's effect |
| C. | Heisenberg's effect |
| D. | Magnetic effect |
| Answer» B. Bohr's effect | |
| 9569. |
A solid conducting sphere of radius \[{{R}_{\text{1}}}\] is surrounded by another concentric hollow conducting sphere of radius \[{{R}_{\text{2}}}\]. The capacitance of this assembly is proportional to [MP PET 2001; UPSEAT 2001] |
| A. | \[\frac{{{R}_{2}}-{{R}_{1}}}{{{R}_{1}}{{R}_{2}}}\] |
| B. | \[\frac{{{R}_{2}}+{{R}_{1}}}{{{R}_{1}}{{R}_{2}}}\] |
| C. | \[\frac{{{R}_{1}}{{R}_{2}}}{{{R}_{1}}+{{R}_{2}}}\] |
| D. | \[\frac{{{R}_{1}}{{R}_{2}}}{{{R}_{2}}-{{R}_{1}}}\] |
| Answer» E. | |
| 9570. |
In an electroplating experiment, m gm of silver is deposited when 4 ampere of current flows for 2 minute. The amount (in gm) of silver deposited by 6 ampere of current for 40 second will be [MNR 1991; UPSEAT 2000; MP PET 2002; Pb. PET 2004; Orissa JEE 2005] |
| A. | 4 m |
| B. | \[m/2\] |
| C. | \[m/4\] |
| D. | 2 m |
| Answer» C. \[m/4\] | |
| 9571. |
For the series LCR circuit shown in the figure, what is the resonance frequency and the amplitude of the current at the resonating frequency [Kerala PET 2005] |
| A. | \[2500\,rad-{{s}^{-1}}\] and \[5\sqrt{2}\,A\] |
| B. | \[2500\,rad-{{s}^{-1}}\] and \[5A\] |
| C. | \[2500\,rad-{{s}^{-1}}\] and \[\frac{5}{\sqrt{2}}A\] |
| D. | \[25\,rad-{{s}^{-1}}\] and \[5\sqrt{2}\,A\] |
| Answer» C. \[2500\,rad-{{s}^{-1}}\] and \[\frac{5}{\sqrt{2}}A\] | |
| 9572. |
The energy required to knock out the electron in the third orbit of a hydrogen atom is equal to [DPMT 1987] |
| A. | \[13.6\ eV\] |
| B. | \[+\frac{13.6}{9}eV\] |
| C. | \[-\frac{13.6}{3}eV\] |
| D. | \[-\frac{3}{13.6}eV\] |
| Answer» C. \[-\frac{13.6}{3}eV\] | |
| 9573. |
Assertion : Where two vibrating tuning forks having frequencies 256 Hz and 512 Hz are held near each other, beats cannot be heard. Reason : The principle of superposition is valid only if the frequencies of the oscillators are nearly equal. |
| 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. | |
| 9574. |
A charge of magnitude \[3e\] and mass \[2m\] is moving in an electric field \[\overrightarrow{E}.\] The acceleration imparted to the charge is [DCE 2004] |
| A. | \[2Ee/3m\] |
| B. | \[3Ee/2m\] |
| C. | \[2m/3Ee\] |
| D. | \[3m/2Ee\] |
| Answer» C. \[2m/3Ee\] | |
| 9575. |
Assertion : If different gases are filled turn by turn at the same pressure in the discharge tube the discharge in them takes place at the same potential. Reason : The discharge depends only on the pressure of discharge tube and not on the ionisation potential of 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» E. If assertion is false but reason is true. | |
| 9576. |
When a lamp is connected in series with capacitor, then [Pb. PMT 2004] |
| A. | Lamp will not glow |
| B. | Lamp will burst out |
| C. | Lamp will glow normally |
| D. | None of these |
| Answer» B. Lamp will burst out | |
| 9577. |
In Thomson's method of determining e/m of electrons [MP PMT 1997 |
| A. | Electric and magnetic fields are parallel to electrons beam |
| B. | Electric and magnetic fields are perpendicular to each other and perpendicular to electrons beam |
| C. | Magnetic field is parallel to the electrons beam |
| D. | Electric field is parallel to the electrons beam |
| Answer» C. Magnetic field is parallel to the electrons beam | |
| 9578. |
Assertion : The temperature at which Centigrade and Fahrenheit thermometers read the same is ? 40°. Reason : There is no relation between Fahrenheit and Centigrade 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» D. If the assertion and reason both are false. | |
| 9579. |
During an adiabatic expansion of 2 moles of a gas, the change in internal energy was found ?50J. The work done during the process is [Pb. PET 1996] |
| A. | Zero |
| B. | 100J |
| C. | ? 50J |
| D. | 50J |
| Answer» E. | |
| 9580. |
A 120 volt ac source is connected across a pure inductor of inductance 0.70 henry. If the frequency of the source is 60 Hz, the current passing through the inductor is [MP PET 1994] |
| A. | 4.55 amps |
| B. | 0.355 amps |
| C. | 0.455 amps |
| D. | 3.55 amps |
| Answer» D. 3.55 amps | |
| 9581. |
Assertion : A rocket works on the principle of conservation of linear momentum. Reason : Whenever there is a change in momentum of one body, the same change occurs in the momentum of the second body of the same system but in the opposite direction. |
| 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. | |
| 9582. |
The saturation vapour pressure of water at 100°C is [EAMCET 1997] |
| A. | 739 mm of mercury |
| B. | 750 mm of mercury |
| C. | 760 mm of mercury |
| D. | 712 mm of mercury |
| Answer» D. 712 mm of mercury | |
| 9583. |
Assertion : Within a glass slab, a double convex air bubble is formed. This air bubble behaves like a converging lens. Reason : Refractive index of air is more than the refractive index of glass. |
| 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. | |
| 9584. |
Assertion : The average speed of an object may be equal to arithmetic mean of individual speed. Reason : Average speed is equal to total distance travelled 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» C. If assertion is true but reason is false. | |
| 9585. |
If the earth stops rotating, the value of ?g? at the equator will [CPMT 1986] |
| A. | Increase |
| B. | Remain same |
| C. | Decrease |
| D. | None of the above |
| Answer» B. Remain same | |
| 9586. |
A particle has displacement of 12 m towards east and 5 m towards north then 6 m vertically upward. The sum of these displacements is [AIIMS 1998] |
| A. | 12 |
| B. | 10.04 m |
| C. | 14.31 m |
| D. | None of these |
| Answer» D. None of these | |
| 9587. |
The resonant frequency of a circuit is f. If the capacitance is made 4 times the initial values, then the resonant frequency will become [RPET 1996] |
| A. | f / 2 |
| B. | 2f |
| C. | f |
| D. | f / 4 |
| Answer» B. 2f | |
| 9588. |
Triple point of water is [CPMT 2002] |
| A. | 273.16°F |
| B. | 273.16 K |
| C. | 273.16°C |
| D. | 273.16 R |
| Answer» C. 273.16°C | |
| 9589. |
The work done in placing a charge of \[8\times {{10}^{-18}}\] coulomb on a condenser of capacity 100 micro-farad is [AIEEE 2003] |
| A. | \[32\times {{10}^{-32}}\,Joule\] |
| B. | \[16\times {{10}^{-32}}\,Joule\] |
| C. | \[3.1\times {{10}^{-26}}\,Joule\] |
| D. | \[4\times {{10}^{-10}}\,Joule\] |
| Answer» B. \[16\times {{10}^{-32}}\,Joule\] | |
| 9590. |
The Avogadro's number is \[6\times {{10}^{23}}\] per gm mole and electronic charge is \[1.6\times {{10}^{-19}}C\]. The Faraday's number is [DPMT 2001] |
| A. | \[6\times {{10}^{23}}\times 1.6\times {{10}^{-19}}\] |
| B. | \[\frac{6\times {{10}^{23}}}{1.6\times {{10}^{-19}}}\] |
| C. | \[\frac{2}{6\times {{10}^{23}}\times 1.6\times {{10}^{-19}}}\] |
| D. | \[\frac{1.6\times {{10}^{-19}}}{6\times {{10}^{23}}}\] |
| Answer» B. \[\frac{6\times {{10}^{23}}}{1.6\times {{10}^{-19}}}\] | |
| 9591. |
A given system undergoes a change in which the work done by the system equals the decrease in its internal energy. The system must have undergone an [Haryana CEE 1996; UPSEAT 2003] |
| A. | Isothermal change |
| B. | Adiabatic change |
| C. | Isobaric change |
| D. | Isochoric change |
| Answer» C. Isobaric change | |
| 9592. |
When a hydrogen atom is raised from the ground state to an excited state [CBSE PMT 1995; AMU (Med.) 1999] |
| A. | P.E. increases and K.E. decreases |
| B. | P.E. decreases and K.E. increases |
| C. | Both kinetic energy and potential energy increase |
| D. | Both K.E. and P.E. decrease |
| Answer» B. P.E. decreases and K.E. increases | |
| 9593. |
Assertion : Capacitor serves as a block for dc and offers an easy path to ac. Reason : Capacitive reactance is inversely proportional to frequency. |
| 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. | |
| 9594. |
A capacitor is a perfect insulator for |
| A. | Alternating currents |
| B. | Direct currents |
| C. | Both ac and dc |
| D. | None of these |
| Answer» C. Both ac and dc | |
| 9595. |
Coefficient of isothermal elasticity \[{{E}_{\theta }}\] and coefficient of adiabatic elasticity \[{{E}_{\varphi }}\]are related by\[(\gamma ={{C}_{p}}/{{C}_{v}})\] [MP PET 2000] |
| A. | \[{{E}_{\theta }}=\gamma \,{{E}_{\varphi }}\] |
| B. | \[{{E}_{\varphi }}=\gamma \,{{E}_{\theta }}\] |
| C. | \[{{E}_{\theta }}=\gamma /{{E}_{\varphi }}\] |
| D. | \[{{E}_{\theta }}={{\gamma }^{2}}{{E}_{\varphi }}\] |
| Answer» C. \[{{E}_{\theta }}=\gamma /{{E}_{\varphi }}\] | |
| 9596. |
Which of the following transitions in a hydrogen atom emits photon of the highest frequency [MP PET 1996; DPMT 2001] |
| A. | n = 1 to n = 2 |
| B. | n = 2 to n = 1 |
| C. | n = 2 to n = 6 |
| D. | n = 6 to n = 2 |
| Answer» B. n = 2 to n = 1 | |
| 9597. |
If eight identical drops are joined to form a bigger drop, the potential on bigger as compared to that on smaller drop will be [RPMT 2002] |
| A. | Double |
| B. | Four times |
| C. | Eight times |
| D. | One time |
| Answer» C. Eight times | |
| 9598. |
In a LCR circuit having L = 8.0 henry, C = 0.5 mF and R = 100 ohm in series. The resonance frequency in per second is [CPMT 1990] |
| A. | 600 radian |
| B. | 600 Hz |
| C. | 500 radian |
| D. | 500 Hz |
| Answer» D. 500 Hz | |
| 9599. |
Assertion : If dot product and cross product of \[\vec{A}\] and \[\vec{B}\] are zero, it implies that one of the vector \[\vec{A}\] and \[\vec{B}\] must be a null vector. Reason : Null vector is a vector with zero magnitude. |
| 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. | |
| 9600. |
A glass rod rubbed with silk is used to charge a gold leaf electroscope and the leaves are observed to diverge. The electroscope thus charged is exposed to X-rays for a short period. Then [AMU 1995] |
| A. | The divergence of leaves will not be affected |
| B. | The leaves will diverge further |
| C. | The leaves will collapse |
| D. | The leaves will melt |
| Answer» C. The leaves will collapse | |