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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.
| 1051. |
Obtain the directions of vector \[(\vec{A}\,-\vec{B}),\] if \[\vec{A}=2\hat{i}+3\hat{j}=\,\hat{k},\vec{B}\,=2\hat{i}+2\hat{j}+3\hat{k}\] |
| A. | \[0,\,\frac{1}{\sqrt{5}}\,,\,\frac{-2}{\sqrt{5}}\] |
| B. | \[0,\,\frac{1}{\sqrt{5}}\,,\,\frac{1}{\sqrt{5}}\] |
| C. | 0, 0, \[\frac{1}{\sqrt{5}}\] |
| D. | None of these |
| Answer» B. \[0,\,\frac{1}{\sqrt{5}}\,,\,\frac{1}{\sqrt{5}}\] | |
| 1052. |
If a unit vector is represented by \[0.5\hat{i}\,+0.8\hat{j}\,+\,c\hat{k},\] then the value of c is |
| A. | 1 |
| B. | \[\sqrt{0.11}\] |
| C. | \[\sqrt{0.01}\] |
| D. | \[\sqrt{0.39}\] |
| Answer» C. \[\sqrt{0.01}\] | |
| 1053. |
Assertion : Steel is more elastic than rubber. Reason : Under given deforming force, steel is deformed less than rubber. |
| 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. | |
| 1054. |
The pressure on a square plate is measured by measuring the force on the plate and length of the sides of the plate by using the formula \[P=\frac{F}{{{\ell }^{2}}}\]. If the maximum errors in the measurement of force and length are 6% and 3% respectively, then the maximum error in the measurement of pressure is |
| A. | 0.01 |
| B. | 2% |
| C. | 12% |
| D. | 10% |
| Answer» D. 10% | |
| 1055. |
In thermal equilibrium, the average velocity of gas molecules is |
| A. | Proportional to \[\sqrt{T}\] |
| B. | Proportional to \[{{T}^{2}}\] |
| C. | Proportional to \[{{T}^{3}}\] |
| D. | Zero |
| Answer» B. Proportional to \[{{T}^{2}}\] | |
| 1056. |
The molecules of a given mass of a gas have a r.m.s. velocity of 200 m/sec at \[27{}^\circ C\] and \[1.0\times {{10}^{5}}\,N/{{m}^{2}}\] pressure. When the temperature is \[127{}^\circ C\]and pressure is \[0.5\times {{10}^{5}}\,N/{{m}^{2}}\], the r.m.s. velocity in m/sec will be |
| A. | \[\frac{100\sqrt{2}}{3}\] |
| B. | \[100\sqrt{2}\] |
| C. | \[\frac{400}{\sqrt{3}}\] |
| D. | None of the above |
| Answer» D. None of the above | |
| 1057. |
On any planet, the presence of atmosphere implies (\[{{C}_{rms}}\]= root mean square velocity of molecules and \[{{V}_{e}}\]= escape velocity) |
| A. | \[{{C}_{rms}}<<{{V}_{e}}\] |
| B. | \[{{C}_{rms}}>{{V}_{e}}\] |
| C. | \[{{C}_{rms}}={{V}_{e}}\] |
| D. | \[{{C}_{rms}}=0\] |
| Answer» B. \[{{C}_{rms}}>{{V}_{e}}\] | |
| 1058. |
A particle is moving in a horizontal circle with constant speed. It has constant [MP PMT 1987; AFMC 1993; CPMT 1997; MP PET 2000] |
| A. | Velocity |
| B. | Acceleration |
| C. | Kinetic energy |
| D. | Displacement |
| Answer» D. Displacement | |
| 1059. |
Assertion : In an elastic collision of two bodies, the momentum and energy of each body is conserved. Reason : If two bodies stick to each other, after colliding, the collision is said to be perfectly elastic. |
| 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. | |
| 1060. |
Which one of the following is not measured in units of energy? |
| A. | Couple x angle |
| B. | Moment of inertia \[\times {{(angular\text{ }velocity)}^{2}}\] |
| C. | \[Force~\,\times \,distance\] |
| D. | \[Impulse\,\times \,time\] |
| Answer» E. | |
| 1061. |
A force acts on a 30gm 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 |
| A. | 576mJ |
| B. | 450mJ |
| C. | 490mJ |
| D. | 530mJ |
| Answer» B. 450mJ | |
| 1062. |
An object of size \[7.5cm\] is placed in front of a convex mirror of radius of curvature \[25cm\] at a distance of \[40cm.\]The size of the image should be |
| A. | \[2.3cm\] |
| B. | \[1.78cm\] |
| C. | \[1cm\] |
| D. | \[0.8cm\] |
| Answer» C. \[1cm\] | |
| 1063. |
The focal length of a concave mirror is \[50cm.\] Where an object be placed so that its image is two times and inverted |
| A. | 75 cm |
| B. | 72 cm |
| C. | 63 cm |
| D. | 50 cm |
| Answer» B. 72 cm | |
| 1064. |
Which of the following is a unit vector? |
| A. | \[\hat{i}+\,\hat{j}\] |
| B. | \[\cos \,\theta \hat{i}-\sin \,\theta \hat{j}\] |
| C. | \[\sin \,\theta \hat{i}+2\,x\cos \theta \hat{j}\] |
| D. | \[\frac{1}{\sqrt{3}}\,(\hat{i}+\,\hat{j})\] |
| Answer» C. \[\sin \,\theta \hat{i}+2\,x\cos \theta \hat{j}\] | |
| 1065. |
A coin is placed on a horizontal platform which undergoes vertical simple harmonic motion of angular frequency co. The amplitude of oscillation is gradually increased. The coin will leave contact with the platform for the first time |
| A. | at the mean position of the platform |
| B. | for an amplitude of \[\frac{g}{{{\omega }^{2}}}\] |
| C. | for an amplitude of\[\frac{g}{{{\omega }^{2}}}\] |
| D. | at the highest position of the platform |
| Answer» C. for an amplitude of\[\frac{g}{{{\omega }^{2}}}\] | |
| 1066. |
Which of the following statements are true regarding Bohr's model of hydrogen atom (I) Orbiting speed of electron decreases as it shifts to discrete orbits away from the nucleus (II) Radii of allowed orbits of electron are proportional to the principal quantum number (III) Frequency with which electrons orbits around the nucleus in discrete orbits is inversely proportional to the principal quantum number (IV) Binding force with which the electron is bound to the nucleus increases as it shifts to outer orbits Select correct answer using the codes given below Codes : [SCRA 1998] |
| A. | I and III |
| B. | II and IV |
| C. | I, II and III |
| D. | II, III and IV |
| Answer» B. II and IV | |
| 1067. |
An alternating voltage is connected in series with a resistance R and an inductance L If the potential drop across the resistance is 200 V and across the inductance is 150 V, then the applied voltage is [CPMT 1990] |
| A. | 350 V |
| B. | 250 V |
| C. | 500 V |
| D. | 300 V |
| Answer» C. 500 V | |
| 1068. |
The displacement of a particle in SHM is\[x=10\sin \left( 2t-\frac{\pi }{6} \right)\] metre. When its displacement is 6 m, the velocity of the particle (in m s~1) is |
| A. | 8 |
| B. | 24 |
| C. | 16 |
| D. | 10 |
| Answer» D. 10 | |
| 1069. |
Assertion : Sine and cosine functions are periodic functions. Reason : Sinusoidal functions repeats it values after a definite interval of 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» B. If both assertion and reason are true but reason is not the correct explanation of the assertion. | |
| 1070. |
Assertion : When a simple pendulum is made to oscillate on the surface of moon, its time period increases. Reason : Moon is much smaller as compared to earth. |
| 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. | |
| 1071. |
Assertion : The graph between velocity and displacement for a harmonic oscillator is a parabola. Reason : Velocity does not change uniformly with displacement in harmonic motion. |
| 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. | |
| 1072. |
When a weight of 10 kg is suspended from a copper wire of length 3 metres and diameter 0.4 mm, its length increases by 2.4 cm. If the diameter of the wire is doubled, then the extension in its length will be [MP PMT 1994] |
| A. | 9.6 cm |
| B. | 4.8 cm |
| C. | 1.2 cm |
| D. | 0.6 cm |
| Answer» E. | |
| 1073. |
Two bodies of masses 2 kg and 4 kg are moving with velocities 2 m/s and 10 m/s respectively along same direction. Then the velocity of their centre of mass will be |
| A. | 8.1 m/s |
| B. | 7.3 m/s |
| C. | 6.4 m/s |
| D. | 5.3 m/s |
| Answer» C. 6.4 m/s | |
| 1074. |
If the velocity \[\upsilon \] of a particle moving along a straight line decreases linearly with its displacement S is \[20\,\,m{{s}^{-1}}\] to a value approaching to zero at \[S=30\,m,\] then acceleration of the particle at \[S=15\text{ }m,\] is |
| A. | \[\frac{2}{3}m{{s}^{-2}}\] |
| B. | \[-\frac{2}{3}m{{s}^{-2}}\] |
| C. | \[\frac{20}{3}m{{s}^{-2}}\] |
| D. | \[-\frac{20}{3}m{{s}^{-2}}\] |
| Answer» E. | |
| 1075. |
A cylinder of mass 10kg is sliding on a plane with an initial velocity of 10m/s. If coefficient of friction between surface and cylinder is 0.5, then before stopping it will describe [Pb. PMT 2001] |
| A. | 12.5 m |
| B. | 5 m |
| C. | 7.5 m |
| D. | 10 m |
| Answer» E. | |
| 1076. |
At NTP, sample of equal volume of chlorine and oxygen is taken. Now ratio of No. of molecules |
| A. | 1 : 1 |
| B. | 1.35208333333333 |
| C. | 0.0840277777777778 |
| D. | 0.676388888888889 |
| Answer» B. 1.35208333333333 | |
| 1077. |
The depletion layer in silicon diode is 1 mm wide and the knee potential is 0.6 V, then the electric field in the depletion layer will be |
| A. | Zero |
| B. | 0.6 Vm?1 |
| C. | 6 ´ 104 V/m |
| D. | 6 ´ 105 V/m |
| Answer» E. | |
| 1078. |
Assertion : A needle placed carefully on the surface of water may float, whereas a ball of the same material will always sink. Reason : The buoyancy of an object depends both on the material and shape of the object. |
| 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. | |
| 1079. |
The reflecting surface of a plane mirror is vertical. A particle is projected in a vertical plane which is also perpendicular to the mirror. The initial speed of the particle is 10 m/s and the angle of projection is \[{{60}^{o}}\] from the normal of the mirror. The point of projection is at a distance 5 m from the mirror. The particle moves towards the mirror. Just before the particle touches the mirror, the velocity of approach of the particle and the image is: |
| A. | 10 m/s |
| B. | 5 m/s |
| C. | \[10\sqrt{3}\,m/s\] |
| D. | \[5\sqrt{3}\,m/s\] |
| Answer» B. 5 m/s | |
| 1080. |
Assertion : The 200 W bulbs glows with more brightness then 100 W bulbs. Reason : A 100 W bulb has more resistance than a 200 W bulb. |
| 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. | |
| 1081. |
The radius of curvature of a plane mirror of length 40 cm is: |
| A. | 20 cm |
| B. | 40 cm |
| C. | 0 |
| D. | None |
| Answer» E. | |
| 1082. |
A straight bar, of mass 15 kg and length 2 m, at rest on a frictionless horizontal surface, receives an instantaneous impulse of 7.5 Ns perpendicular to the bar. If the impulse is applied at the mid-point of the bar, the energy transferred is |
| A. | 3.2 J |
| B. | 1.9J |
| C. | 3.8 J |
| D. | 2.5 J |
| Answer» C. 3.8 J | |
| 1083. |
A particle is executing the motion \[x=A\cos (\omega \,t-\theta )\]. The maximum velocity of the particle is [BHU 2003; CPMT 2004] |
| A. | \[A\omega \cos \theta \] |
| B. | \[A\omega \] |
| C. | \[A\omega \sin \theta \] |
| D. | None of these |
| Answer» C. \[A\omega \sin \theta \] | |
| 1084. |
The room heater can maintain only \[16{}^\circ C\] in the room when the temperature outside is \[-20{}^\circ C\]. It is not warm and comfortable, that is why the electric stove with power of 1 kW is also plugged in. Together these two devices maintain the room temperature of \[22{}^\circ C\]. Determine the thermal power of the heater. |
| A. | 3 kW |
| B. | 4 kW |
| C. | 5 kW |
| D. | 6 kW |
| Answer» E. | |
| 1085. |
When the nucleus of a radium-226, which is at rest, decays, an \[\alpha \] particle and the nucleus of radon are created. The released energy during the decay is 4.87 MeV, which appears as the kinetic energy of the two resulted particles. Calculate the kinetic energy of a particle and radon nucleus. |
| A. | 4.78 MeV and 0.09 MeV |
| B. | 4.67 MeV and 0.2 MeV |
| C. | 4.84 MeV and 0.03 MeV |
| D. | 4.81 MeV and 0.06 MeV |
| Answer» B. 4.67 MeV and 0.2 MeV | |
| 1086. |
Assertion : Radiation is the speediest mode of heat transfer. Reason : Radiation can be transmitted in zig-zag motion. |
| 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. | |
| 1087. |
Assertion : The force of repulsion between atomic nucleus and a-particle varies with distance according to inverse square law. Reason : Rutherford did a-particle scattering experiment. |
| 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. | |
| 1088. |
The force required to keep a body in uniform circular motion is [EAMCET 1982; AFMC 2003] |
| A. | Centripetal force |
| B. | Centrifugal force |
| C. | Resistance |
| D. | None of the above |
| Answer» B. Centrifugal force | |
| 1089. |
The carrier frequency generated by a tank circuit containing 1 nF capacitor and 10 mH inductor is [AFMC 2003] |
| A. | 1592 Hz |
| B. | 1592 MHz |
| C. | 1592 kHz |
| D. | 159.2 Hz |
| Answer» D. 159.2 Hz | |
| 1090. |
E, m, J and G denote energy, mass, angular momentum and gravitational constant respectively, then the unit of \[\frac{E{{J}^{2}}}{{{m}^{5}}{{G}^{2}}}\]is |
| A. | Newton |
| B. | metre |
| C. | Kilogram |
| D. | unitless |
| Answer» E. | |
| 1091. |
Volume of gas become four times if |
| A. | Temperature become four times at constant pressure |
| B. | Temperature become one fourth at constant pressure |
| C. | Temperature becomes two times at constant pressure |
| D. | Temperature becomes half at constant pressure |
| Answer» B. Temperature become one fourth at constant pressure | |
| 1092. |
The elastic energy stored in a wire of Young's modulus Y is [MP PMT 1999] |
| A. | \[Y\times \frac{\text{Strai}{{\text{n}}^{\text{2}}}}{\text{Volume}}\] |
| B. | Stress \[\times \] Strain \[\times \] Volume |
| C. | \[\frac{\text{Stres}{{\text{s}}^{\text{2}}}\times \text{Volume}}{2Y}\] |
| D. | \[\frac{1}{2}Y\times \] Stress \[\times \] Strain \[\times \] Volume |
| Answer» D. \[\frac{1}{2}Y\times \] Stress \[\times \] Strain \[\times \] Volume | |
| 1093. |
The lengths and radii of two rods made of same material are in the ratios 1 : 2 and 2 : 3 respectively. If the temperature difference between the ends for the two rods be the same, then in the steady state, the amount of heat flowing per second through them will be in the ratio [MP PET 2000] |
| A. | 1: 3 |
| B. | 4 : 3 |
| C. | 8 : 9 |
| D. | 3 : 2 |
| Answer» D. 3 : 2 | |
| 1094. |
If an electron oscillates at a frequency of 1 GHz it gives [DCE 1999] |
| A. | X-rays |
| B. | Mirowaves |
| C. | Infrared rays |
| D. | None of these |
| Answer» E. | |
| 1095. |
Assertion : If the displacement of the body is zero, the distance covered by it may not be zero. Reason : Displacement is a vector quantity and distance is a scalar quantity. |
| 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. | |
| 1096. |
When two sound waves travel in the same direction in a medium, the displacements of a particle located at 'x' at time 't' is given by: \[{{y}_{1}}=0.05\cos (0.50\pi x-100\pi t)\] \[{{y}_{2}}=0.05\cos (0.46\pi x-92\pi t)\] Where\[{{y}_{1}}\] , \[{{y}_{2}}\] and x are in meters and t seconds. The speed of sound in the medium is: |
| A. | 92m/s |
| B. | 200 m/s |
| C. | 100m/s |
| D. | 332m/s |
| Answer» C. 100m/s | |
| 1097. |
A person with his hands in his pockets is skating on ice at the velocity of 10 m/s and describes a circle of radius 50 m. What is his inclination with vertical [Pb. PET 2000] |
| A. | \[\frac{\sqrt{3}}{2}.\] |
| B. | \[{{\tan }^{-1}}\left( \frac{3}{5} \right)\] |
| C. | \[{{\tan }^{-1}}(1)\] |
| D. | \[{{\tan }^{-1}}\left( \frac{1}{5} \right)\] |
| Answer» E. | |
| 1098. |
On a linear temperature scale Y, water freezes at \[160{}^\circ Y\]and boils at \[- 50{}^\circ Y\]. On this Y scale, a temperature of 340 K would be read as : (water freezes at 273 K and boils at 373 K) |
| A. | \[-73.7{}^\circ Y\] |
| B. | \[-\,233.7{}^\circ Y\] |
| C. | \[-86.3{}^\circ Y\] |
| D. | \[-106.3{}^\circ Y\] |
| Answer» D. \[-106.3{}^\circ Y\] | |
| 1099. |
A polaroid is placed at \[45{}^\circ \] to an incoming light of intensity I. Now the intensity of light after polarisation would be |
| A. | I |
| B. | \[I/2\] |
| C. | \[I/\sqrt{2}\] |
| D. | zero |
| Answer» C. \[I/\sqrt{2}\] | |
| 1100. |
de-Broglie wavelength of a body of mass m and kinetic energy E is given by |
| A. | \[\lambda =\frac{h}{mE}\] |
| B. | \[\lambda =\frac{\sqrt{2mE}}{h}\] |
| C. | \[\lambda =\frac{h}{2mE}\] |
| D. | \[\lambda =\frac{h}{\sqrt{2mE}}\] |
| Answer» E. | |