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.
| 401. |
Assertion : In series LCR circuit resonance can take place. Reason : Resonance takes place if inductance and capacitive reactances are equal and opposite. [AIIMS 1998] |
| 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. | |
| 402. |
Assertion : The refractive index of diamond is \[\sqrt{6}\] and that of liquid is \[\sqrt{3}\]. If the light travels from diamond to the liquid, it will totally reflected when the angle of incidence is 30o. Reason : \[\mu =\frac{1}{\sin C},\] where m is the refractive index of diamond with respect to liquid. [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» F. | |
| 403. |
Unit of surface tension is [Orissa PMT 2004] |
| A. | \[N{{m}^{-1}}\] |
| B. | \[N{{m}^{-2}}\] |
| C. | \[{{N}^{2}}{{m}^{-1}}\] |
| D. | \[N{{m}^{-3}}\] |
| Answer» B. \[N{{m}^{-2}}\] | |
| 404. |
When a longitudinal wave propagates through a medium, the particles of the medium execute simple harmonic oscillations about their mean positions. These oscillations of a particle are characterized by an invariant |
| A. | kinetic energy |
| B. | potential energy |
| C. | sum of kinetic energy and potential energy |
| D. | difference between kinetic energy and potential energy |
| Answer» D. difference between kinetic energy and potential energy | |
| 405. |
Which relation is wrong [RPMT 1997] |
| A. | 1 Calorie = 4.18 Joules |
| B. | \[1\overset{\text{o}}{\mathop{\text{A}}}\,={{10}^{-10}}m\] |
| C. | \[1\,\,MeV=1.6\times {{10}^{-13}}Joules\] |
| D. | \[1\,Newton={{10}^{-5}}Dynes\] |
| Answer» E. | |
| 406. |
The de-Broglie wavelength \[\lambda \] associated with an electron having kinetic energy E is given by the expression |
| A. | \[\frac{h}{\sqrt{2mE}}\] |
| B. | \[\frac{2h}{mE}\] |
| C. | \[2mhE\] |
| D. | \[\frac{2\sqrt{2mE}}{h}\] |
| Answer» B. \[\frac{2h}{mE}\] | |
| 407. |
The de-Broglie wavelength of an electron having \[80eV\] of energy is nearly (\[1\,eV=\text{ }1.6\times {{10}^{19}}J,\] Mass of electron \[=9\times {{10}^{-31}}kg\] Planks constant \[=6.6\times {{10}^{-34}}J\text{-}\,\sec \]) |
| A. | 140 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] |
| B. | 0.14 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] |
| C. | 14 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] |
| D. | 1.4 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] |
| Answer» C. 14 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] | |
| 408. |
A stone tied to a string is rotated in a circle. If the string is cut, the stone flies away from the circle because |
| A. | A centrifugal force acts on the stone |
| B. | A centripetal force acts on the stone |
| C. | Of its inertia |
| D. | Reaction of the centripetal force |
| Answer» D. Reaction of the centripetal force | |
| 409. |
The first diffraction minimum due to the single slit diffraction is seen at \[9=30{}^\circ \] for a light of wavelength 5000 A falling perpendicularly on the slit. The width of the slit is |
| A. | \[2.5\times {{10}^{-5}}cm\] |
| B. | \[1.25\times {{10}^{-5}}cm\] |
| C. | \[10\times {{10}^{-5}}cm\] |
| D. | \[5\times {{10}^{-5}}cm\] |
| Answer» D. \[5\times {{10}^{-5}}cm\] | |
| 410. |
Assertion : In photoemissive cell inert gas is used. Reason : Inert gas in the photoemissive cell gives greater current. |
| 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. | |
| 411. |
In the given curve of the above question, find the value of angle \[{{i}_{1}}\] in degrees. |
| A. | \[{{40}^{o}}\] |
| B. | \[{{60}^{o}}\] |
| C. | \[{{70}^{o}}\] |
| D. | \[{{90}^{o}}\] |
| Answer» E. | |
| 412. |
If a man throws up a ball and catches it after some time, this time is called time of flight. Time of flight in these types of motion depend on whether the man is stationary or he is accelerated. If the man is in a moving lift throws a ball and catches it after time \[{{t}_{1}}\] when lift is moving up with acceleration a and catches the ball in time \[{{t}_{2}}\] if the lift is moving down with same acceleration a. The speed with which ball is thrown w.r.t. man - |
| A. | \[\frac{g{{t}_{1}}{{t}_{2}}}{{{t}_{1}}-{{t}_{2}}}\] |
| B. | \[\frac{g{{t}_{1}}{{t}_{2}}}{{{t}_{1}}+{{t}_{2}}}\] |
| C. | \[\frac{2g{{t}_{1}}{{t}_{2}}}{{{t}_{1}}-{{t}_{2}}}\] |
| D. | \[\frac{2g{{t}_{1}}{{t}_{2}}}{{{t}_{1}}+{{t}_{2}}}\] |
| Answer» C. \[\frac{2g{{t}_{1}}{{t}_{2}}}{{{t}_{1}}-{{t}_{2}}}\] | |
| 413. |
The time period of a simple pendulum when it is made to oscillate on the surface of moon [J & K CET 2004] |
| A. | Increases |
| B. | Decreases |
| C. | Remains unchanged |
| D. | Becomes infinite |
| Answer» B. Decreases | |
| 414. |
A force acts on a 30 gm particle in such a way that the position of the particle as a function of time is given by \[x=3t-4{{t}^{2}}+{{t}^{3}}\], where x is in metres and t is in seconds. The work done during the first 4 seconds is [CBSE PMT 1998] |
| A. | 5.28 J |
| B. | 450 mJ |
| C. | 490 mJ |
| D. | 530 mJ |
| Answer» B. 450 mJ | |
| 415. |
In Young's double slit experiment, the distance between the two slits is 0.1 mm and the wavelength of light used is \[4\times {{10}^{-7}}m\]. If the width of the fringe on the screen is 4 mm, the distance between screen and slit is [Bihar CMEET 1995] |
| A. | 0.1 mm |
| B. | 1 cm |
| C. | 0.1 cm |
| D. | 1 m |
| Answer» E. | |
| 416. |
A simple harmonic oscillator has a period of 0.01 sec and an amplitude of 0.2 m. The magnitude of the velocity in \[m{{\sec }^{-1}}\] at the centre of oscillation is [JIPMER 1997] |
| A. | \[20\pi \] |
| B. | 100 |
| C. | 40p |
| D. | \[100\pi \] |
| Answer» D. \[100\pi \] | |
| 417. |
An engineer claims to have made an engine delivering 10kW power with fuel consumption of 1 g/s. The calorific value of fuel is 2 kcal/g. This claim is |
| A. | Valid |
| B. | Invalid |
| C. | Depends on engine design |
| D. | Dependent on load |
| Answer» C. Depends on engine design | |
| 418. |
The mean distance between the atoms of iron is \[3\times {{10}^{-10}}m\] and interatomic force constant for iron is \[7\,N\,/m\]The Young?s modulus of elasticity for iron is [JIPMER 2002] |
| A. | \[2.33\times {{10}^{5}}\,N/{{m}^{2}}\] |
| B. | \[23.3\times {{10}^{10}}\,N/{{m}^{2}}\] |
| C. | \[233\times {{10}^{10}}\,N/{{m}^{2}}\] |
| D. | \[2.33\times {{10}^{10}}\,N/{{m}^{2}}\] |
| Answer» E. | |
| 419. |
20 ampere current is flowing in a long straight wire. The intensity of magnetic field at a distance 10 cm from the wire will be [Pb. PMT 2003] |
| A. | 4 ´ 10?5 Wb/m2 |
| B. | 9 ´ 10?5 Wb/m2 |
| C. | 8 ´ 10?5 Wb/m2 |
| D. | 6 ´ 10?5 Wb/m2 |
| Answer» B. 9 ´ 10?5 Wb/m2 | |
| 420. |
A physical quantity \[\zeta \]is calulated using the formula\[\zeta =\frac{1}{10}x{{y}^{2}}/{{z}^{1/3}}\], where x, y and z are experimentally measured quantities. If the fractional error in the measurement of x, y and z are 2 %, 1% and 3% respectively, then the fractional error in\[\zeta \]will be |
| A. | 0.005 |
| B. | 5% |
| C. | 6% |
| D. | 7% |
| Answer» C. 6% | |
| 421. |
A load W produces an extension of 1mm in a thread of radius r. Now if the load is made 4W and radius is made 2r all other things remaining same, the extension will become [RPET 2000] |
| A. | 4 mm |
| B. | 16 mm |
| C. | 1 mm |
| D. | 0.25 mm |
| Answer» D. 0.25 mm | |
| 422. |
The magnitude of the centripetal force acting on a body of mass \[m\] executing uniform motion in a circle of radius \[r\] with speed \[v\] is [AFMC 1998; MP PET 1999] |
| A. | \[mvr\] |
| B. | \[\nu =\sqrt{\frac{rg(\tan \theta +\mu )}{1-\mu \tan \theta }}\] |
| C. | \[v/{{r}^{2}}m\] |
| D. | \[v/rm\] |
| Answer» C. \[v/{{r}^{2}}m\] | |
| 423. |
Assertion : A man sitting in a boat which is floating on a pond. If the man drinks some water from the pond, the level of the water in the pond decreases. Reason : According to Archimede's principle the weight displaced by body is equal to the weight of the body. |
| 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. | |
| 424. |
One day in a room a heater connected to supply maintained temperature \[20{}^\circ C\] when outside temperature was \[-20{}^\circ C\]. Another day with the same heater, in the same room, temperature was \[10{}^\circ C\] when outside temperature was \[-40{}^\circ C\]. If temperature of heater is same both the days. Find this value. (use \[\frac{dT}{dt}=k(T-{{T}_{0}})\] and k is same for both days). |
| A. | \[120{}^\circ C\] |
| B. | \[30{}^\circ C\] |
| C. | \[40{}^\circ C\] |
| D. | \[60{}^\circ C\] |
| Answer» E. | |
| 425. |
The angular speed of seconds needle in a mechanical watch is [RPMT 1999; CPMT 1997; MH CET 2000, 01; BHU 2000] |
| A. | \[\frac{\pi }{30}\]rad/s |
| B. | \[2\pi \]rad/s |
| C. | \[\pi \]rad/s |
| D. | \[\frac{60}{\pi }\]rad/s |
| Answer» B. \[2\pi \]rad/s | |
| 426. |
A body executes simple harmonic motion. The potential energy (P.E.), the kinetic energy (K.E.) and total energy (T.E.) are measured as a function of displacement x. Which of the following statement is true? |
| A. | P.E. is maximum when x = 0. |
| B. | K.E. is maximum when x = 0. |
| C. | T. E. is zero when x = 0. |
| D. | K.E. is maximum when x is maximum. |
| Answer» C. T. E. is zero when x = 0. | |
| 427. |
A bulb is connected first with dc and then ac of same voltage then it will shine brightly with [RPET 2000] |
| A. | AC |
| B. | DC |
| C. | Brightness will be in ratio 1/1.4 |
| D. | Equally with both |
| Answer» E. | |
| 428. |
A ball is allowed to fall from a height of 10 m. If there is 40% loss of energy due to air friction, then velocity of the ball when it hit the ground is |
| A. | \[\sqrt{190}m/s\] |
| B. | \[\sqrt{180}m/s\] |
| C. | \[\sqrt{150}m/s\] |
| D. | \[\sqrt{120}m/s\] |
| Answer» E. | |
| 429. |
In a Carnot engine, the temperature of reservoir is \[927{}^\circ C\] and that of sink is\[27{}^\circ C\]. If the work done by the engine when it transfers heat from reservoir to sink is \[12.6\times {{10}^{6}}J,\] the quantity of heat absorbed by the engine from the reservoir is |
| A. | \[16.8\times {{10}^{6}}J\] |
| B. | \[4\times {{10}^{6}}J\] |
| C. | \[7.6\times {{10}^{6}}J\] |
| D. | \[4.2\times {{10}^{6}}J\] |
| Answer» B. \[4\times {{10}^{6}}J\] | |
| 430. |
Assertion : Semiconductors do not Obey's Ohm's law. Reason : Current is determined by the rate of flow of charge carriers. |
| 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. | |
| 431. |
Forces \[{{F}_{1}}\] and \[{{F}_{2}}\] act on a point mass in two mutually perpendicular directions. The resultant force on the point mass will be [CPMT 1991] |
| A. | \[{{F}_{1}}+{{F}_{2}}\] |
| B. | \[{{F}_{1}}-{{F}_{2}}\] |
| C. | \[\sqrt{F_{1}^{2}+F_{2}^{2}}\] |
| D. | \[F_{1}^{2}+F_{2}^{2}\] |
| Answer» D. \[F_{1}^{2}+F_{2}^{2}\] | |
| 432. |
Natural length of a spring is 60 cm, and its spring constant is 4000 N/m. A mass of 20 kg is hung from it. The extension produced in the spring is, (Take \[g=9.8\ m/{{s}^{2}}\]) [DCE 2004] |
| A. | 4.9 cm |
| B. | 0.49 cm |
| C. | 9.4 cm |
| D. | 0.94 cm |
| Answer» B. 0.49 cm | |
| 433. |
A spherical body of mass m and radius r is allowed to fall in a medium of viscosity\[\eta \]. The time in which the velocity of the body increases from zero to 0.63 times the terminal velocity (v) is called time constant\[(\tau )\]. Dimensionally \[\tau \] can be represented by: |
| A. | \[\frac{m{{r}^{2}}}{6\pi \eta }\] |
| B. | \[\sqrt{\left( \frac{6\pi mr\eta }{{{g}^{2}}} \right)}\] |
| C. | \[\frac{m}{6\pi \eta rv}\] |
| D. | None of these |
| Answer» E. | |
| 434. |
The root mean square velocity of a gas molecule of mass m at a given temperature is proportional to |
| A. | \[{{m}^{0}}\] |
| B. | m |
| C. | \[\sqrt{m}\] |
| D. | \[\frac{1}{\sqrt{m}}\] |
| Answer» E. | |
| 435. |
If \[Z={{A}^{3}}\], then \[\frac{\Delta Z}{Z}=\_\_\_\_\] |
| A. | \[\frac{\Delta {{A}^{3}}}{A}\] |
| B. | \[{{\left( \frac{\Delta {{A}^{{}}}}{A} \right)}^{3}}\] |
| C. | \[3\left( \frac{\Delta {{A}^{{}}}}{A} \right)\] |
| D. | \[{{\left( \frac{\Delta {{A}^{{}}}}{A} \right)}^{1/3}}\] |
| Answer» D. \[{{\left( \frac{\Delta {{A}^{{}}}}{A} \right)}^{1/3}}\] | |
| 436. |
Assertion : Corpuscular theory fails in explaining the velocities of light in air and water. Reason : According to corpuscular theory, light should travel faster in denser medium than, in rarer medium. [AIIMS 1998] |
| 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. | |
| 437. |
The phase difference between the instantaneous velocity and acceleration of a particle executing simple harmonic motion is |
| A. | \[\pi \] |
| B. | 0.707\[\pi \] |
| C. | zero |
| D. | 0.5\[\pi \] |
| Answer» E. | |
| 438. |
A long solenoid is formed by winding 20 turns/cm. The current necessary to produce a magnetic field of 20 millitesla inside the solenoid will be approximately \[(\frac{{{\mu }_{0}}}{4\pi }={{10}^{-7}}\,tesla-metre/ampere)\] [MP PMT 1994] |
| A. | 8.0 A |
| B. | 4.0 A |
| C. | 2.0 A |
| D. | 1.0 A |
| Answer» B. 4.0 A | |
| 439. |
In the figure shown a thin parallel beam of light is incident on a plane mirror \[{{m}_{1}}\] at small angle \['\theta '.\] \[{{m}_{2}}\] is a concave mirror of focal length \['f'\]. After three successive reflections of this beam the \[x\] and \[y\] coordinates of the image is |
| A. | \[x=f-d,y=f\theta \] |
| B. | \[x=d+f,y=f\theta \] |
| C. | \[x=f-d,y=-f\theta \] |
| D. | \[x=d-f,y=-f\theta \] |
| Answer» E. | |
| 440. |
The system shown in figure is released from rest. The spring gets elongated |
| A. | for M > m |
| B. | for M > 2 m |
| C. | for \[M>\frac{m}{2}\] |
| D. | for any value of M |
| Answer» E. | |
| 441. |
Assertion : The following circuit represents 'OR' gate Reason : For the above circuit \[Y=\bar{X}=\overline{\overline{A+B}}=A+B\] |
| 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. | |
| 442. |
Assertion : A bird perches on a high power line and nothing happens to the bird. Reason : The level of bird is very high from the ground. |
| 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. | |
| 443. |
A stone is tied to one end of a string 50 cm long is whirled in a horizontal circle with a constant speed. If the stone makes 10 revolutions in 20 s, what is the magnitude of acceleration of the stone [Pb. PMT 2000] |
| A. | 493 cm/s2 |
| B. | 720 cm/s2 |
| C. | 860 cm/s2 |
| D. | 990 cm/s2 |
| Answer» B. 720 cm/s2 | |
| 444. |
If \[\alpha ,\,\,\beta \] and \[\gamma \] are coefficient of linear, area and volume expansion respectively, then |
| A. | \[\gamma = 3\alpha \] |
| B. | \[\alpha = 3\gamma \] |
| C. | \[\beta = 3\alpha \] |
| D. | \[\gamma = 3\beta \] |
| Answer» B. \[\alpha = 3\gamma \] | |
| 445. |
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. | |
| 446. |
A zener diode, having breakdown voltage equal to \[15V,\] is used in a voltage regulator circuit shown in figure. The current through the diode is |
| A. | \[10\,mA\] |
| B. | \[15\,mA\] |
| C. | \[20\,mA\] |
| D. | \[5\,mA\] |
| Answer» E. | |
| 447. |
Assertion : A red object appears dark in the yellow light Reason : A red colour is scattered less [AIIMS 2004] |
| 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. | |
| 448. |
Assertion : The stars twinkle while the planets do not. Reason : The stars are much bigger in size than the planets. [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. | |
| 449. |
Two thin symmetrical lenses of different nature and of different material have equal radii of curvature R = 15 cm. The lenses are put close together and immersed in water \[(a=4/3).\] The focal length of the system in water is 30 cm. The difference between refractive indices of the two lenses is |
| A. | 1/2 |
| B. | 1/4 |
| C. | 44256 |
| D. | 44289 |
| Answer» D. 44289 | |
| 450. |
If an object is placed \[10cm\] infront of a concave mirror of focal length \[20cm,\] the image will be [MP PMT 1995] |
| A. | Diminished, upright, virtual |
| B. | Enlarged, upright, virtual |
| C. | Diminished, inverted, real |
| D. | Enlarged, upright, real |
| Answer» C. Diminished, inverted, real | |