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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.
| 1101. |
The approximate wavelength of a photon of energy 2.48 eV is |
| A. | 500 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] |
| B. | 5000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] |
| C. | 2000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] |
| D. | 1000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] |
| Answer» C. 2000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] | |
| 1102. |
A block is placed on a frictionless horizontal table. The mass of the block is m and springs are attached on either side with force constants \[{{K}_{1}}\]and\[{{K}_{2}}\]. If the block is displaced a little and left to oscillate, then the angular frequency of oscillation will be [MP PMT 1994] |
| A. | \[{{\left( \frac{{{K}_{1}}+{{K}_{2}}}{m} \right)}^{1/2}}\] |
| B. | \[{{\left[ \frac{{{K}_{1}}{{K}_{2}}}{m({{K}_{1}}+{{K}_{2}})} \right]}^{1/2}}\] |
| C. | \[{{\left[ \frac{{{K}_{1}}{{K}_{2}}}{({{K}_{1}}-{{K}_{2}})m} \right]}^{1/2}}\] |
| D. | \[{{\left[ \frac{K_{1}^{2}+K_{2}^{2}}{({{K}_{1}}+{{K}_{2}})m} \right]}^{1/2}}\] |
| Answer» B. \[{{\left[ \frac{{{K}_{1}}{{K}_{2}}}{m({{K}_{1}}+{{K}_{2}})} \right]}^{1/2}}\] | |
| 1103. |
A mass m =100 gms is attached at the end of a light spring which oscillates on a frictionless horizontal table with an amplitude equal to 0.16 metre and time period equal to 2 sec. Initially the mass is released from rest at t = 0 and displacement \[x=-0.16\] metre. The expression for the displacement of the mass at any time t is [MP PMT 1995] |
| A. | \[x=0.16\cos (\pi t)\] |
| B. | \[x=-\,0.16\cos (\pi t)\] |
| C. | \[x=0.16\sin (\pi t+\pi )\] |
| D. | \[x=-\,0.16\sin (\pi t+\pi )\] |
| Answer» C. \[x=0.16\sin (\pi t+\pi )\] | |
| 1104. |
A uniform spring of force constant k is cut into two pieces, the lengths of which are in the ratio 1 : 2. The ratio of the force constants of the shorter and the longer pieces is [Manipal MEE 1995] |
| A. | 1 : 3 |
| B. | 1 : 2 |
| C. | 2 : 3 |
| D. | 2 : 1 |
| Answer» E. | |
| 1105. |
For an optical fiber consists of a core (refractive index =\[{{\mu }_{1}}\]) and cladding (refractive index =\[{{\mu }_{2}}\]) |
| A. | \[{{\mu }_{1}}>{{\mu }_{2}}\] |
| B. | \[{{\mu }_{1}}<{{\mu }_{2}}\] |
| C. | \[{{\mu }_{1}}={{\mu }_{2}}\] |
| D. | \[\frac{{{\mu }_{1}}}{{{\mu }_{2}}}=\frac{1}{2}\] |
| Answer» B. \[{{\mu }_{1}}<{{\mu }_{2}}\] | |
| 1106. |
A prism placed in air made up of flint glass is such that any incident ray on one surface does not emerge from the second surface. Critical angle for flint glass is \[36{}^\circ \] in air. Then, refracting angle A may be |
| A. | \[37{}^\circ ~\] |
| B. | \[54{}^\circ \] |
| C. | \[71{}^\circ \] |
| D. | \[73{}^\circ \] |
| Answer» E. | |
| 1107. |
Assertion : Voltameter measures current more accurately than ammeter. Reason : Relative error will be small if measured from voltameter. |
| 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. | |
| 1108. |
In the Young?s experiment, If length of wire and radius both are doubled then the value of \[Y\] will become [RPET 2003] |
| A. | 2 times |
| B. | 4 times |
| C. | Remains same |
| D. | Half |
| Answer» D. Half | |
| 1109. |
Assertion : In isothermal process whole of the heat energy supplied to the body is converted into internal energy. Reason : According to the first law of thermodynamics \[\Delta Q=\Delta U+p\Delta V\]. [AIIMS 1997] |
| 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. | |
| 1110. |
The wavelength of the energy emitted when electron come from fourth orbit to second orbit in hydrogen is \[20.397\,cm\]. The wavelength of energy for the same transition in \[H{{e}^{+}}\] is |
| A. | \[5.099\ c{{m}^{-1}}\] |
| B. | \[20.497\ c{{m}^{-1}}\] |
| C. | \[40.994\ c{{m}^{-1}}\] |
| D. | \[81.988\ c{{m}^{-1}}\] |
| Answer» B. \[20.497\ c{{m}^{-1}}\] | |
| 1111. |
The depletion layer in the P-N junction region is caused by [CBSE PMT 1994] |
| A. | Drift of holes |
| B. | Diffusion of charge carriers |
| C. | Migration of impurity ions |
| D. | Drift of electrons |
| Answer» C. Migration of impurity ions | |
| 1112. |
The ground state energy of hydrogen atom is ? 13.6 eV. What is the potential energy of the electron in this state [AIIMS 2005] |
| A. | 0 eV |
| B. | ? 27.2 eV |
| C. | 1 eV |
| D. | 2 eV |
| Answer» C. 1 eV | |
| 1113. |
Car is accelerating with acceleration = 20 m/s2. A box of mass m = 10 kg that is placed inside the car it is put in contact with the vertical wall of car as shown. The friction coefficient between the box and the wall is \[\mu =0.6\]. |
| A. | The acceleration of the box will be \[10\,m/{{\sec }^{2}}\] |
| B. | The friction force acting on the box will be 100 N |
| C. | The contact force between the vertical wall and the box will be 100 N |
| D. | None of these |
| Answer» C. The contact force between the vertical wall and the box will be 100 N | |
| 1114. |
A string is producing transverse vibration whose equation is \[y=0.021\ \sin (x+30t)\], Where x and y are in meters and \[t\] is in seconds. If the linear density of the string is \[1.3\times {{10}^{-4}}\]kg/m, then the tension in the string in \[N\] will be [RPET 1999; RPMT 2002] |
| A. | 10 |
| B. | 0.5 |
| C. | 1 |
| D. | 0.117 |
| Answer» E. | |
| 1115. |
If vibrations of a string are to be increased by a factor of two, then tension in the string must be made [AIIMS 1999; Pb. PET 2000] |
| A. | Half |
| B. | Twice |
| C. | Four times |
| D. | Eight times |
| Answer» D. Eight times | |
| 1116. |
If the tension of sonometer?s wire increases four times then the fundamental frequency of the wire will increase by [RPMT 1999] |
| A. | 2 times |
| B. | 4 times |
| C. | 1/2 times |
| D. | None of the above |
| Answer» B. 4 times | |
| 1117. |
The average power dissipation in a pure capacitance in ac circuit is [DPMT 1987; MP PMT/PET 1998] |
| A. | \[\frac{1}{2}C{{V}^{2}}\] |
| B. | \[C{{V}^{2}}\] |
| C. | \[\frac{1}{4}C{{V}^{2}}\] |
| D. | Zero |
| Answer» E. | |
| 1118. |
Assertion : Magnetic moment of helium atom is zero. Reason : All the electron are paired in helium atom orbitals. |
| 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. | |
| 1119. |
The capacitance of an air capacitor is \[15\mu F\]the separation between the parallel plates is\[6mm\]. A copper plate of \[3mm\] thickness is introduced symmetrically between the plates. The capacitance now becomes [MP PMT 1995] |
| A. | \[5\mu F\] |
| B. | \[7.5\mu F\] |
| C. | \[22.5\mu F\] |
| D. | \[30\mu F\] |
| Answer» E. | |
| 1120. |
A plastic hemisphere has a radius of curvature of 8 cm and an index of refraction of 1.6. On the axis halfway between the plane surface and the spherical one (4 cm from each) is a small object O. The distance between the two images when viewed along the axis from the two sides of the hemisphere is approximately |
| A. | 1.0 cm |
| B. | 1.5 cm |
| C. | 3.75 cm |
| D. | 2.5 cm |
| Answer» E. | |
| 1121. |
If a particle under S.H.M. has time period 0.1 sec and amplitude \[{{\tan }^{-1}}\frac{a}{g}\]. It has maximum velocity [RPET 2000] |
| A. | \[\frac{\pi }{25}\,m/s\] |
| B. | \[\frac{\pi }{26}\,m/s\] |
| C. | \[{{\tan }^{-1}}\frac{a}{g}\] |
| D. | None of these |
| Answer» B. \[\frac{\pi }{26}\,m/s\] | |
| 1122. |
A car moves on a circular road. It describes equal angles about the centre in equal intervals of time. Which of the following statement about the velocity of the car is true [BHU 2001] |
| A. | Magnitude of velocity is not constant |
| B. | Both magnitude and direction of velocity change |
| C. | Velocity is directed towards the centre of the circle |
| D. | Magnitude of velocity is constant but direction changes |
| Answer» E. | |
| 1123. |
When a gas expands adiabatically [CPMT 1990] |
| A. | No energy is required for expansion |
| B. | Energy is required and it comes from the wall of the container of the gas |
| C. | Internal energy of the gas is used in doing work |
| D. | Law of conservation of energy does not hold |
| Answer» D. Law of conservation of energy does not hold | |
| 1124. |
No bias is applied to a P-N junction, then the current [RPMT 1999] |
| A. | Is zero because the number of charge carriers flowing on both sides is same |
| B. | Is zero because the charge carriers do not move |
| C. | Is non-zero |
| D. | None of these |
| Answer» C. Is non-zero | |
| 1125. |
When the state of a gas adiabatically changed from an equilibrium state A to another equilibrium state B an amount of work done on the system is 35 J. If the gas is taken from state A to B via process in which the net heat absorbed by the system is 12 cal, then the net work done by the system is \[\left( 1\text{ }cal=4.19J \right)\] |
| A. | 13.2 J |
| B. | 15.4 J |
| C. | 12.6 J |
| D. | 16.8 J |
| Answer» C. 12.6 J | |
| 1126. |
Maximum value of static friction is called [BHU 1995; RPET 2000] |
| A. | Limiting friction |
| B. | Rolling friction |
| C. | Normal reaction |
| D. | Coefficient of friction |
| Answer» B. Rolling friction | |
| 1127. |
A man sets his watch by a whistle that is 2 km away. How much will his watch be in error. (speed of sound in air 330 m/sec) [MP PET 1991] |
| A. | 3 seconds fast |
| B. | 3 seconds slow |
| C. | 6 seconds fast |
| D. | 6 seconds slow |
| Answer» E. | |
| 1128. |
The acceleration of a particle undergoing SHM is graphed in figure. At point 2 the velocity of the particle is |
| A. | zero |
| B. | negative |
| C. | positive |
| D. | None of these |
| Answer» B. negative | |
| 1129. |
Maximum useable frequency (MUF) in F-region layer is x, when the critical frequency is 60 MHz and the angle of incidence is 70°. Then x is [Himachal PMT 2003] |
| A. | 150 MHz |
| B. | 170 MHz |
| C. | 175 MHz |
| D. | 190 MHz |
| Answer» D. 190 MHz | |
| 1130. |
In the depletion region of an unbiased P-N junction diode there are [KCET 1999; CBSE PMT 1999; RPMT 2001; MP PMT 1994, 2003] |
| A. | Only electrons |
| B. | Only holes |
| C. | Both electrons and holes |
| D. | Only fixed ions |
| Answer» E. | |
| 1131. |
A wavelength 0.60 cm is produced in air and it travels at a speed of 300 ms?1. It will be an [UPSEAT 2000] |
| A. | Audible wave |
| B. | Infrasonic wave |
| C. | Ultrasonic wave |
| D. | None of the above |
| Answer» D. None of the above | |
| 1132. |
500 g of water and 100 g of ice at \[0{}^\circ C\]are in a calorimeter whose water equivalent is 40 g. 10 g of steam at \[100{}^\circ C\] is added to it. Then water in the calorimeter is : (Latent heat of ice =80 cal/g, Latent heat of steam =540 cal/ g) |
| A. | 580 g |
| B. | 590 g |
| C. | 600 g |
| D. | 610 g |
| Answer» C. 600 g | |
| 1133. |
At what angle should the two forces 2P and \[\sqrt{2}\,P\] act so that the resultant force is \[P\sqrt{10}\,?\] |
| A. | \[45{}^\circ \] |
| B. | \[{{60}^{o}}\] |
| C. | \[{{90}^{o}}\] |
| D. | \[{{120}^{o}}\] |
| Answer» B. \[{{60}^{o}}\] | |
| 1134. |
A transistor connected in common emitter con- figuration has input resistance \[{{R}_{B}}=2\,k\Omega \] and load resistance of \[5\,k\Omega \]. If \[\beta =60\] and an input signal \[12\text{ }mV\] is applied, calculate the voltage gain, the power gain and the value of output voltage |
| A. | \[{{A}_{V}}=150,\,\,{{V}_{out}}=1.8\,V,\] and power gain \[=9000\] |
| B. | \[{{A}_{V}}=20,\,{{V}_{out}}=1V,\]and power gain \[=2000\] |
| C. | \[{{A}_{V}}=150,\,{{V}_{out}}=1.5V,\] and power gain \[=8500\] |
| D. | \[{{A}_{V}}=20,\,{{V}_{out}}=1.5V,\] and power gain\[=2000\] |
| Answer» B. \[{{A}_{V}}=20,\,{{V}_{out}}=1V,\]and power gain \[=2000\] | |
| 1135. |
A thin copper wire of length / metre increases in length by 2% when heated through\[10{}^\circ C\]. What is the percentage increase in area when a square copper sheet of length / metre is heated through \[10{}^\circ C?\] |
| A. | 0.04 |
| B. | 8% |
| C. | 16% |
| D. | None of these |
| Answer» B. 8% | |
| 1136. |
A machine gun fires 20 bullets per second into a target. Each bullet weighs 150 gms and has a speed of 800 m/sec. Find the force necessary to hold the gun in position [EAMCET 1994] |
| A. | 800 N |
| B. | 1000 N |
| C. | 1200 N |
| D. | 2400 N |
| Answer» E. | |
| 1137. |
A ring of mass m can slide over a smooth vertical rod as shown in figure. The ring is connected to a spring of force constant\[k=4mg\text{ }I\text{ }R\], where 2 R is the natural length of the spring. The other end of spring is fixed to the ground at a horizontal distance 2 R from the base of the rod. If the mass is released at a height 1.5 R, then the velocity of the ring as it reaches the ground is Critical Thinking |
| A. | \[\sqrt{gR}\] |
| B. | \[2\sqrt{gR}\] |
| C. | \[\sqrt{2gR}\] |
| D. | \[\sqrt{3gR}\] |
| Answer» C. \[\sqrt{2gR}\] | |
| 1138. |
Length cannot be measured by [AIIMS 2002] |
| A. | Fermi |
| B. | Debye |
| C. | Micron |
| D. | Light year |
| Answer» C. Micron | |
| 1139. |
A diode having potential difference 0.5 V across its junction which does not depend on current, is connected in series with resistance of 20 W across source. If 0.1 A passes through resistance then what is the voltage of the source [DCE 2005] |
| A. | 1.5 V |
| B. | 2.0 V |
| C. | 2.5 V |
| D. | 5 V |
| Answer» D. 5 V | |
| 1140. |
Assertion : Current is passed through a metallic wire, heating it red. When cold water is poured on half of its portion, then rest of the half portion become more hot. Reason : Resistances decreases due to decrease in temperature and so current through wire increases. |
| 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. | |
| 1141. |
When we touch the terminals of a high voltage capacitor, even after a high voltage has been cut off, then the capacitor has a tendency to [AFMC 2000] |
| A. | Restore energy |
| B. | Discharge energy |
| C. | Affect dangerously |
| D. | Both B and C |
| Answer» E. | |
| 1142. |
In the above figure D and E respectively represent [CPMT 1986, 88] |
| A. | Absorption line of Balmer series and the ionization potential of hydrogen |
| B. | Absorption line of Balmer series and the wavelength lesser than lowest of the Lyman series |
| C. | Spectral line of Balmer series and the maximum wavelength of Lyman series |
| D. | Spectral line of Lyman series and the absorption of greater wavelength of limiting value of Paschen series |
| Answer» B. Absorption line of Balmer series and the wavelength lesser than lowest of the Lyman series | |
| 1143. |
Zener breakdown takes place if [RPMT 2000] |
| A. | Doped impurity is low |
| B. | Doped impurity is high |
| C. | Less impurity in N-part |
| D. | Less impurity in P-type |
| Answer» C. Less impurity in N-part | |
| 1144. |
Tesla is a unit for measuring [CBSE PMT 1993] |
| A. | Magnetic moment |
| B. | Magnetic induction |
| C. | Magnetic intensity |
| D. | Magnetic pole strength |
| Answer» 2 , 3. Magnetic intensity | |
| 1145. |
Heat required to convert one gram of ice at 0°C into steam at 100°C is (given Lsteam = 536 cal/gm) [Pb. PMT 1990] |
| A. | 100 calorie |
| B. | 0.01 kilocalorie |
| C. | 716 calorie |
| D. | 1 kilocalorie |
| Answer» D. 1 kilocalorie | |
| 1146. |
If the linear momentum is increased by 50%, the kinetic energy will increase by [CPMT 1983; MP PMT 1994; MP PET 1996, 99; UPSEAT 2001] |
| A. | 50% |
| B. | 100% |
| C. | 125% |
| D. | 25% |
| Answer» D. 25% | |
| 1147. |
A 1 kg particle at a height of 8m has a speed of 1 Om/s down a fixed incline making an angle \[53{}^\circ \] with horizontal as shown in figure. It slides on a horizontal section of length 10 m at ground level and then up a fixed incline making an angle \[37{}^\circ \] with horizontal. All surfaces have\[{{\mu }_{k}} = 0.5\]. How far (in meters) from point 0 (bottom of right inclined plane), along the incline making an angle \[37{}^\circ \] with horizontal, does the particle first come to rest? |
| A. | 1m |
| B. | 0.5m |
| C. | 2m |
| D. | 5m |
| Answer» B. 0.5m | |
| 1148. |
Assertion : Like light radiations, thermal radiations are also electromagnetic radiation. Reason : The thermal radiations require no medium for propagation. |
| 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. | |
| 1149. |
If M the mass of the earth and R its radius, the ratio of the gravitational acceleration and the gravitational constant is [J&K CET 2005] |
| A. | \[\frac{{{R}^{2}}}{M}\] |
| B. | \[\frac{M}{{{R}^{2}}}\] |
| C. | \[M{{R}^{2}}\] |
| D. | \[\frac{M}{R}\] |
| Answer» C. \[M{{R}^{2}}\] | |
| 1150. |
A mass of 4 kg suspended from a spring of force constant 800 N m~1 executes simple harmonic oscillations. If the total energy of the oscillator is 4 J, the maximum acceleration (\[in\,m\,{{s}^{-2}}\]) of the mass is |
| A. | 5 |
| B. | 15 |
| C. | 45 |
| D. | 20 |
| Answer» E. | |