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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.
| 1601. |
A point source has been placed as shown in the figure. What is the length on the screen that will receive reflected light from the mirror? |
| A. | 2H |
| B. | 3H |
| C. | H |
| D. | None of these |
| Answer» B. 3H | |
| 1602. |
Assertion : Average value of ac over a complete cycle is always zero. Reason : Average value of ac is always defined over half cycle. |
| 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. | |
| 1603. |
In hydrogen atom, when electron jumps from second to first orbit, then energy emitted is [AIEEE 2002] |
| A. | ? 13.6 eV |
| B. | ? 27.2 eV |
| C. | ? 6.8 eV |
| D. | None of these |
| Answer» E. | |
| 1604. |
A gas mixture consists of 2 mol of oxygen and 4 mol of argon at temperature T. Neglecting all vibrational modes, the total internal energy of the system is |
| A. | 4 RT |
| B. | 15 RT |
| C. | 9 RT |
| D. | 11 RT |
| Answer» E. | |
| 1605. |
At what temperature is the rms velocity of a hydrogen molecule equal to that of an oxygen molecule at \[47{}^\circ C\]? |
| A. | 80 K |
| B. | 3 K |
| C. | - 73 K |
| D. | 20 K |
| Answer» E. | |
| 1606. |
Work function of a metal is 2.1 eV. Which of the waves of the following wavelengths will be able to emit photoelectrons from its surface |
| A. | 4000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\], 7500 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] |
| B. | 5500 \[\overset{\text{o}}{\mathop{\text{A}}}\,\], 6000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] |
| C. | 4000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\], 6000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] |
| D. | None of these |
| Answer» E. | |
| 1607. |
A beam of light of wavelength \[\lambda \] and with illumination L falls on a clean surface of sodium. If N photoelectrons are emitted each with kinetic energy E, then |
| A. | \[N\propto L\] and \[E\propto L\] |
| B. | \[N\propto L\]and \[E\propto \frac{1}{\lambda }\] |
| C. | \[N\propto \lambda \] and \[E\propto L\] |
| D. | \[N\propto \frac{1}{\lambda }\]and \[E\propto \frac{1}{L}\] |
| Answer» C. \[N\propto \lambda \] and \[E\propto L\] | |
| 1608. |
Cathode rays enter into a uniform magnetic field perpendicular to the direction of the field. In the magnetic field their path will be [MP PMT/PET 1998] |
| A. | Straight line |
| B. | Circle |
| C. | Parabolic |
| D. | Ellipse |
| Answer» C. Parabolic | |
| 1609. |
Assertion : When a solid iron ball is heated, percentage increase is its volume is largest. Reason : Coefficient of superficial expansion is twice that of linear expansion where as coefficient of volume expansion is three time of linear expansion. |
| 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. | |
| 1610. |
64 drops each having the capacity \[C\] and potential \[V\]are combined to form a big drop. If the charge on the small drop is\[q\], then the charge on the big drop will be [MP PET 1985; MP PET/PMT 1988; CPMT 1971] |
| A. | \[2q\] |
| B. | \[4q\] |
| C. | \[16q\] |
| D. | \[64q\] |
| Answer» E. | |
| 1611. |
The motion of a particle varies with time according to the relation \[y=a(\sin \omega \,t+\cos \omega \,t)\], then |
| A. | The motion is oscillatory but not S.H.M. |
| B. | The motion is S.H.M. with amplitude a |
| C. | The motion is S.H.M. with amplitude \[a\sqrt{2}\] |
| D. | The motion is S.H.M. with amplitude \[2a\] |
| Answer» D. The motion is S.H.M. with amplitude \[2a\] | |
| 1612. |
The resultant of two rectangular simple harmonic motions of the same frequency and unequal amplitudes but differing in phase by \[\frac{\pi }{2}\] is [BHU 2003; CPMT 2004; MP PMT 1989, 2005; BCECE 2005] |
| A. | Simple harmonic |
| B. | Circular |
| C. | Elliptical |
| D. | Parabolic |
| Answer» D. Parabolic | |
| 1613. |
The composition of two simple harmonic motions of equal periods at right angle to each other and with a phase difference of \[\pi \] results in the displacement of the particle along [CBSE PMT 1990] |
| A. | Straight line |
| B. | Circle |
| C. | Ellipse |
| D. | Figure of eight |
| Answer» B. Circle | |
| 1614. |
Two sound waves of slightly different frequencies propagating in the same direction produce beats due to [MP PET 2000] |
| A. | Interference |
| B. | Diffraction |
| C. | Polarization |
| D. | Refraction |
| Answer» B. Diffraction | |
| 1615. |
Maximum number of beats frequency heard by a human being is [RPMT 2000] |
| A. | 10 |
| B. | 4 |
| C. | 20 |
| D. | 6 |
| Answer» B. 4 | |
| 1616. |
\[t={{t}_{1}}+{{t}_{2}}=\frac{M}{R}(C\Delta T+L)\] A glass flask is filled up to a mark with 50 cc of mercury at \[18{}^\circ C\]. If the flask and contents are heated to \[38{}^\circ C,\] how much mercury will be above the mark? (\[\alpha \] for glass is \[9\times {{10}^{-6}}/{}^\circ C\] and coefficient of real expansion of mercury is\[180\times {{10}^{-6}}/{}^\circ C\]) |
| A. | 0.85 cc |
| B. | 0.46 cc |
| C. | 0.153 cc |
| D. | 0.05 cc |
| Answer» D. 0.05 cc | |
| 1617. |
The coefficient of apparent expansion of mercury in a glass vessel is \[153\times {{10}^{-6}}/{}^\circ C\] and in a steel vessel is \[144\times {{10}^{-6}}/{}^\circ C\]. If \[\alpha \] for steel is \[12\times {{10}^{-6}}/{}^\circ C,\] then that of glass is |
| A. | \[9\times {{10}^{-6}}/{}^\circ C\] |
| B. | \[6\times {{10}^{-6}}/{}^\circ C\] |
| C. | \[36\times {{10}^{-6}}/{}^\circ C\] |
| D. | \[27\times {{10}^{-6}}/{}^\circ C\] |
| Answer» B. \[6\times {{10}^{-6}}/{}^\circ C\] | |
| 1618. |
A solid object of mass M is made of material of specific heat capacity c, latent heat of fusion L and of very high thermal conductivity. When the object enters the atmosphere from outer space, its temperature below its melting point by \[\Delta T\]. Because of atmospheric friction, it absorbs energy at a constant rate of R. The time before the solid becomes completely molten is |
| A. | \[\frac{M(C+L)\Delta T}{R}\] |
| B. | \[\frac{M(C\Delta T+L)}{R}\] |
| C. | \[\frac{M(C+L)\Delta T}{R}\] |
| D. | \[\frac{R}{(M\Delta T(C+L)}\] |
| Answer» C. \[\frac{M(C+L)\Delta T}{R}\] | |
| 1619. |
The device that does not work on the principle of mutual induction is [KCET 1994] |
| A. | Induction coil |
| B. | Motor |
| C. | Tesla coil |
| D. | Transformer |
| Answer» D. Transformer | |
| 1620. |
Radius of gyration of a body depends upon |
| A. | axis of rotation |
| B. | translational motion |
| C. | shape of the body |
| D. | area of the body |
| Answer» B. translational motion | |
| 1621. |
A block of mass 100 gm slides on a rough horizontal surface. If the speed of the block decreases from 10 m/s to 5 m/s, the thermal energy developed in the process is |
| A. | 3.75 J |
| B. | 37.5 J |
| C. | 0.375 J |
| D. | 0.75 J |
| Answer» B. 37.5 J | |
| 1622. |
5 g of ice at \[0{}^\circ C\] is dropped in a beaker containing 20 g of water at \[40{}^\circ C\]. The final temperature will be |
| A. | \[32{}^\circ C\] |
| B. | \[16{}^\circ C\] |
| C. | \[8{}^\circ C\] |
| D. | \[24{}^\circ C\] |
| Answer» C. \[8{}^\circ C\] | |
| 1623. |
A closed bottle containing water at \[30{}^\circ C\] is carried to the moon in a space-ship. If it is placed on the surface of the moon, what will happen to the water as soon as the lid is opened |
| A. | Water will boil |
| B. | Water will freeze |
| C. | Nothing will happen on it |
| D. | It will decompose into \[{{H}_{2}}\] and \[{{O}_{2}}\] |
| Answer» B. Water will freeze | |
| 1624. |
The thermal capacity of a body is 80 cal, then its water equivalent is |
| A. | 80 cal / gm |
| B. | 8 gm |
| C. | 80 gm |
| D. | 80 kg |
| Answer» D. 80 kg | |
| 1625. |
X-rays were discovered by [NCERT 1977; BHU 2005] |
| A. | Becquerel |
| B. | Roentgen |
| C. | Marie Curie |
| D. | Von Laue |
| Answer» C. Marie Curie | |
| 1626. |
The resistance of a resistance thermometer has values 2.71 and 3.70 ohm at \[10{}^\circ C\] and \[100{}^\circ C\]. The temperature at which the resistance is 3.26 ohm is |
| A. | \[40{}^\circ C\] |
| B. | \[50{}^\circ C\] |
| C. | \[60{}^\circ C\] |
| D. | \[70{}^\circ C\] |
| Answer» C. \[60{}^\circ C\] | |
| 1627. |
Assertion : When an object is placed between two plane parallel mirrors, then all the images found are of equal intensity. Reason : In case of plane parallel mirrors, only two images are possible. |
| 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. | |
| 1628. |
Assertion : The polar caps of earth are cold in comparison to equatorial plane. Reason : The radiation absorbed by polar caps is less than the radiation absorbed by equatorial plane. |
| 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. | |
| 1629. |
Assertion : The illumination of earth's surface from sun is more at noon than in the morning. Reason : Luminance of a surface refers to brightness of the surface. |
| 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. | |
| 1630. |
Assertion : An electron and proton enters a magnetic field with equal velocities, then, the force experienced by the proton will be more than electron. Reason : The mass of proton is 1837 times more than electron. |
| 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. | |
| 1631. |
Standing waves can be produced [IIT-JEE 1999] |
| A. | On a string clamped at both the ends |
| B. | On a string clamped at one end and free at the other |
| C. | When incident wave gets reflected from a wall |
| D. | When two identical waves with a phase difference of p are moving in the same direction |
| Answer» B. On a string clamped at one end and free at the other | |
| 1632. |
In stationary waves, antinodes are the points where there is [MP PMT 1996] |
| A. | Minimum displacement and minimum pressure change |
| B. | Minimum displacement and maximum pressure change |
| C. | Maximum displacement and maximum pressure change |
| D. | Maximum displacement and minimum pressure change |
| Answer» E. | |
| 1633. |
In stationary waves all particles between two nodes pass through the mean position [MP PMT 1999; KCET 2001] |
| A. | At different times with different velocities |
| B. | At different times with the same velocity |
| C. | At the same time with equal velocity |
| D. | At the same time with different velocities |
| Answer» E. | |
| 1634. |
The value of plate current in the given circuit diagram will be |
| A. | 3 mA |
| B. | 8 mA |
| C. | 13 mA |
| D. | 18 mA |
| Answer» D. 18 mA | |
| 1635. |
The relation between phase difference (Df) and path difference (Dx) is [MNR 1995; UPSEAT 1999, 2000] |
| A. | \[\Delta \varphi =\frac{2\pi }{\lambda }\Delta x\] |
| B. | \[\Delta \varphi =2\pi \lambda \Delta x\] |
| C. | \[\Delta \varphi =\frac{2\pi \lambda }{\Delta x}\] |
| D. | \[\Delta \varphi =\frac{2\Delta x}{\lambda }\] |
| Answer» B. \[\Delta \varphi =2\pi \lambda \Delta x\] | |
| 1636. |
A 2 kg block slides on a horizontal floor with a speed of4m/s. It strikes a uncompressed spring, and compresses it till the block is motionless. The kinetic friction force is 15N and spring constant is 10,000 N/m. The spring compresses by Critical Thinking |
| A. | 8.5 cm |
| B. | 5.5 cm |
| C. | 2.5 cm |
| D. | 11.0 cm |
| Answer» C. 2.5 cm | |
| 1637. |
In a hydrogen atom, the distance between the electron and proton is \[2.5\times {{10}^{-11}}\,m\]. The electrical force of attraction between them will be [Pb. PMT 2000] |
| A. | \[2.8\times {{10}^{-7}}\,N\] |
| B. | \[3.7\times {{10}^{-7}}N\] |
| C. | \[6.2\times {{10}^{-7}}N\] |
| D. | \[9.1\times {{10}^{-7}}N\] |
| Answer» C. \[6.2\times {{10}^{-7}}N\] | |
| 1638. |
If the ratio of the concentration of electrons to that of holes in a semiconductor is \[\frac{7}{5}\] and the ratio of currents is \[\frac{7}{4},\] then what is the ratio of their drift velocities? |
| A. | \[\frac{5}{8}\] |
| B. | \[\frac{4}{5}\] |
| C. | \[\frac{5}{4}\] |
| D. | \[\frac{4}{7}\] |
| Answer» D. \[\frac{4}{7}\] | |
| 1639. |
The thermionic emission of electron is due to [UPSEAT 2000] |
| A. | Electromagnetic field |
| B. | Electrostatic field |
| C. | High temperature |
| D. | Photoelectric effect |
| Answer» D. Photoelectric effect | |
| 1640. |
A piece of copper and the other of germanium are cooled from the room temperature to 80 K, then which of the following would be a correct statement [IIT-JEE 1988; Bihar CEE 1992; CBSE PMT 1993; MP PET 1997; RPET 1999; AIEEE 2004] |
| A. | Resistance of each increases |
| B. | Resistance of each decreases |
| C. | Resistance of copper increases while that of germanium decreases |
| D. | Resistance of copper decreases while that of germanium increases |
| Answer» E. | |
| 1641. |
A virtual image three times the size of the object is obtained with a concave mirror of radius of curvature \[36cm.\]The distance of the object from the mirror is [MP PET 1986] |
| A. | \[5cm\] |
| B. | \[12cm\] |
| C. | \[10cm\] |
| D. | \[20cm\] |
| Answer» C. \[10cm\] | |
| 1642. |
A silicon diode has a threshold voltage of \[0.7\text{ }V\]. If an input voltage given by \[2\sin (\pi t)\] is supplied to a half wave rectifier circuit using this diode, the rectified output has a peak value of |
| A. | \[2V\] |
| B. | \[1.4V\] |
| C. | \[1.3V\] |
| D. | \[0.7\,V\] |
| Answer» D. \[0.7\,V\] | |
| 1643. |
Radius of curvature of concave mirror is \[40cm\] and the size of image is twice as that of object, then the object distance is [AFMC 1995] |
| A. | \[60cm\] |
| B. | \[20cm\] |
| C. | \[40cm\] |
| D. | \[30cm\] |
| Answer» E. | |
| 1644. |
Energy needed in breaking a drop of radius R into n drops of radii r is given by [CPMT 1982, 97] |
| A. | \[4\pi T(n{{r}^{2}}-{{R}^{2}})\] |
| B. | \[\frac{4}{3}\pi ({{r}^{3}}n-{{R}^{2}})\] |
| C. | \[4\pi T({{R}^{2}}-n{{r}^{2}})\] |
| D. | \[4\pi T(n{{r}^{2}}+{{R}^{2}})\] |
| Answer» B. \[\frac{4}{3}\pi ({{r}^{3}}n-{{R}^{2}})\] | |
| 1645. |
A particle comes round a circle of radius 1 m once. The time taken by it is 10 sec. The average velocity of motion is [JIPMER 1999] |
| A. | 0.2 \[\pi m/s\] |
| B. | \[2\,\,\pi m/s\] |
| C. | 2 \[m/s\] |
| D. | Zero |
| Answer» E. | |
| 1646. |
An object is placed at a distance of 50 cm from a convex mirror. A plane mirror is placed in front of the convex mirror in such a way that it convers half of the convex mirror. If the distance between object and plane mirror is 30 cm then there is no parallax between the images formed by two mirrors the radius of curvature of convex mirror will be : |
| A. | 50 cm |
| B. | 25 cm |
| C. | 12.5 cm |
| D. | 100 cm |
| Answer» C. 12.5 cm | |
| 1647. |
An infinitely long rectangular strip is placed on principal axis of a concave mirror as shown in figure. One end of the strip coincides with centre of curvature as shown. The height of rectangular strip is very small in comparison to focal length of the mirror. Then the shape of image of strip formed by concave mirror is |
| A. | Rectangle |
| B. | Trapezium |
| C. | Triangle |
| D. | Square |
| Answer» D. Square | |
| 1648. |
The correct statement from the following is [MP PET 1993] |
| A. | A body having zero velocity will not necessarily have zero acceleration |
| B. | A body having zero velocity will necessarily have zero acceleration |
| C. | A body having uniform speed can have only uniform acceleration |
| D. | A body having non-uniform velocity will have zero acceleration |
| Answer» B. A body having zero velocity will necessarily have zero acceleration | |
| 1649. |
A body weight 500 N on the surface of the earth. How much would it weigh half way below the surface of the earth [Pb. PET 2001; BHU 2004] |
| A. | 125 N |
| B. | 250 N |
| C. | 500 N |
| D. | 1000 N |
| Answer» C. 500 N | |
| 1650. |
The value of \[{{C}_{p}}-{{C}_{v}}=1.00R\] for a gas in state A and \[{{C}_{p}}-{{C}_{v}}=1.06R\] in another state. If \[{{P}_{A}}\] and \[{{P}_{B}}\] denote the pressure and \[{{T}_{A}}\] and \[{{T}_{B}}\] denote the temperatures in the two states, respectively, then |
| A. | \[{{P}_{A}}={{P}_{B}},\,{{T}_{A}}>{{T}_{B}}\] |
| B. | \[{{P}_{A}}>{{P}_{B}},\,{{P}_{A}}={{T}_{B}}\] |
| C. | \[{{P}_{A}}<{{P}_{B}},\,{{P}_{A}}>{{P}_{B}}\] |
| D. | \[{{P}_{A}}>{{P}_{B}},\,{{T}_{A}}<{{T}_{B}}\] |
| Answer» D. \[{{P}_{A}}>{{P}_{B}},\,{{T}_{A}}<{{T}_{B}}\] | |