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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.
| 6901. |
According to Bernoulli's equation \[\frac{P}{\rho g}+h+\frac{1}{2}\,\frac{{{v}^{2}}}{g}=\text{constant}\] The terms A, B and C are generally called respectively: |
| A. | Gravitational head, pressure head and velocity head |
| B. | Gravity, gravitational head and velocity head |
| C. | Pressure head, gravitational head and velocity head |
| D. | Gravity, pressure and velocity head |
| Answer» D. Gravity, pressure and velocity head | |
| 6902. |
The weight of an aeroplane flying in air is balanced by |
| A. | Upthrust of the air which will be equal to the weight of the air having the same volume as the plane |
| B. | Force due to the pressure difference between the upper and lower surfaces of the wings, created by different air speeds on the surface |
| C. | Vertical component of the thrust created by air currents striking the lower surface of the wings |
| D. | Force due to the reaction of gases ejected by the revolving propeller |
| Answer» C. Vertical component of the thrust created by air currents striking the lower surface of the wings | |
| 6903. |
At what speed the velocity head of a stream of water be equal to 40 cm of Hg |
| A. | 282.8 cm/sec |
| B. | 432.6 cm/sec |
| C. | 632.6 cm/sec |
| D. | 832.6 cm/sec |
| Answer» B. 432.6 cm/sec | |
| 6904. |
The pans of a physical balance are in equilibrium. Air is blown under the right hand pan; then the right hand pan will |
| A. | Move up |
| B. | Move down |
| C. | Move erratically |
| D. | Remain at the same level |
| Answer» C. Move erratically | |
| 6905. |
An application of Bernoulli's equation for fluid flow is found in [IIT-JEE (Screening) 1994] |
| A. | Dynamic lift of an aeroplane |
| B. | Viscosity meter |
| C. | Capillary rise |
| D. | Hydraulic press |
| Answer» B. Viscosity meter | |
| 6906. |
An incompressible liquid flows through a horizontal tube as shown in the following fig. Then the velocity v of the fluid is |
| A. | 3.0 m/s |
| B. | 1.5 m/s |
| C. | 1.0 m/s |
| D. | 2.25 m/s |
| Answer» D. 2.25 m/s | |
| 6907. |
In a streamline flow |
| A. | The speed of a particle always remains same |
| B. | The velocity of a particle always remains same |
| C. | The kinetic energies of all the particles arriving at a given point are the same |
| D. | The moments of all the particles arriving at a given point are the same |
| Answer» B. The velocity of a particle always remains same | |
| 6908. |
Water is flowing through a horizontal pipe of non-uniform cross-section. At the extreme narrow portion of the pipe, the water will have [MP PMT 1992] |
| A. | Maximum speed and least pressure |
| B. | Maximum pressure and least speed |
| C. | Both pressure and speed maximum |
| D. | Both pressure and speed least |
| Answer» B. Maximum pressure and least speed | |
| 6909. |
Water is flowing through a tube of non-uniform cross-section ratio of the radius at entry and exit end of the pipe is 3 : 2. Then the ratio of velocities at entry and exit of liquid is [RPMT 2001] |
| A. | 4 : 9 |
| B. | 9 : 4 |
| C. | 8 : 27 |
| D. | 1 : 1 |
| Answer» B. 9 : 4 | |
| 6910. |
The Reynolds number of a flow is the ratio of |
| A. | Gravity to viscous force |
| B. | Gravity force to pressure force |
| C. | Inertia forces to viscous force |
| D. | Viscous forces to pressure forces |
| Answer» D. Viscous forces to pressure forces | |
| 6911. |
In a turbulent flow, the velocity of the liquid molecules in contact with the walls of the tube is |
| A. | Zero |
| B. | Maximum |
| C. | Equal to critical velocity |
| D. | May have any value |
| Answer» E. | |
| 6912. |
We have two (narrow) capillary tubes T1 and T2. Their lengths are l1 and l2 and radii of cross-section are r1 and r2 respectively. The rate of flow of water under a pressure difference P through tube T1 is 8cm3/sec. If l1 = 2l2 and r1 =r2, what will be the rate of flow when the two tubes are connected in series and pressure difference across the combination is same as before (= P) |
| A. | 4 cm3/sec |
| B. | (16/3) cm3/sec |
| C. | (8/17) cm3/sec |
| D. | None of these |
| Answer» C. (8/17) cm3/sec | |
| 6913. |
A liquid is flowing in a horizontal uniform capillary tube under a constant pressure difference P. The value of pressure for which the rate of flow of the liquid is doubled when the radius and length both are doubled is [EAMCET 2001] |
| A. | P |
| B. | \[\frac{3P}{4}\] |
| C. | \[\frac{P}{2}\] |
| D. | \[\frac{P}{4}\] |
| Answer» E. | |
| 6914. |
Two water pipes of diameters 2 cm and 4 cm are connected with the main supply line. The velocity of flow of water in the pipe of 2 cm diameter is [MNR 1980] |
| A. | 4 times that in the other pipe |
| B. | \[\frac{1}{4}\] times that in the other pipe |
| C. | 2 times that in the other pipe |
| D. | \[\frac{1}{2}\] times that in the other pipe |
| Answer» B. \[\frac{1}{4}\] times that in the other pipe | |
| 6915. |
The rate of steady volume flow of water through a capillary tube of length 'l' and radius 'r' under a pressure difference of P is V. This tube is connected with another tube of the same length but half the radius in series. Then the rate of steady volume flow through them is (The pressure difference across the combination is P) [EAMCET (Engg.) 2003] |
| A. | \[\frac{V}{16}\] |
| B. | \[\frac{V}{17}\] |
| C. | \[\frac{16V}{17}\] |
| D. | \[\frac{17V}{16}\] |
| Answer» C. \[\frac{16V}{17}\] | |
| 6916. |
Two drops of the same radius are falling through air with a steady velocity of 5 cm per sec. If the two drops coalesce, the terminal velocity would be [MP PMT 1990] |
| A. | 10 cm per sec |
| B. | 2.5 cm per sec |
| C. | \[5\times {{(4)}^{1/3}}cm\] per sec |
| D. | \[5\times \sqrt{2}\,cm\] per sec |
| Answer» D. \[5\times \sqrt{2}\,cm\] per sec | |
| 6917. |
A small sphere of mass m is dropped from a great height. After it has fallen 100 m, it has attained its terminal velocity and continues to fall at that speed. The work done by air friction against the sphere during the first 100 m of fall is [MP PMT 1990] |
| A. | Greater than the work done by air friction in the second 100 m |
| B. | Less than the work done by air friction in the second 100 m |
| C. | Equal to 100 mg |
| D. | Greater than 100 mg |
| Answer» C. Equal to 100 mg | |
| 6918. |
A ball of radius r and density r falls freely under gravity through a distance h before entering water. Velocity of ball does not change even on entering water. If viscosity of water is h, the value of h is given by |
| A. | \[\frac{2}{9}{{r}^{2}}\left( \frac{1-\rho }{\eta } \right)\,g\] |
| B. | \[\frac{2}{81}{{r}^{2}}\left( \frac{\rho -1}{\eta } \right)\,g\] |
| C. | \[\frac{2}{81}{{r}^{4}}{{\left( \frac{\rho -1}{\eta } \right)}^{2}}g\] |
| D. | \[\frac{2}{9}{{r}^{4}}{{\left( \frac{\rho -1}{\eta } \right)}^{2}}g\] |
| Answer» D. \[\frac{2}{9}{{r}^{4}}{{\left( \frac{\rho -1}{\eta } \right)}^{2}}g\] | |
| 6919. |
Spherical balls of radius 'r' are falling in a viscous fluid of viscosity 'h' with a velocity 'v'. The retarding viscous force acting on the spherical ball is [AIEEE 2004] |
| A. | Inversely proportional to 'r' but directly proportional to velocity 'v' |
| B. | Directly proportional to both radius 'r' and velocity 'v' |
| C. | Inversely proportional to both radius 'r' and velocity 'v' |
| D. | Directly proportional to 'r' but inversely proportional to 'v' |
| Answer» C. Inversely proportional to both radius 'r' and velocity 'v' | |
| 6920. |
There is a hole in the bottom of tank having water. If total pressure at bottom is 3 atm (1 atm = 105N/m2) then the velocity of water flowing from hole is [CPMT 2002] |
| A. | \[\sqrt{400}\,m/s\] |
| B. | \[\sqrt{600\,}\,m/s\] |
| C. | \[\sqrt{60}\,m/s\] |
| D. | None of these |
| Answer» B. \[\sqrt{600\,}\,m/s\] | |
| 6921. |
There is a hole of area A at the bottom of cylindrical vessel. Water is filled up to a height h and water flows out in t second. If water is filled to a height 4h, it will flow out in time equal to [MP PMT 1997] |
| A. | t |
| B. | 4t |
| C. | 2 t |
| D. | t/4 |
| Answer» D. t/4 | |
| 6922. |
A cylindrical tank has a hole of 1 cm2 in its bottom. If the water is allowed to flow into the tank from a tube above it at the rate of 70 cm3/sec. then the maximum height up to which water can rise in the tank is |
| A. | 2.5 cm |
| B. | 5 cm |
| C. | 10 cm |
| D. | 0.25 cm |
| Answer» B. 5 cm | |
| 6923. |
A cylinder of height 20 m is completely filled with water. The velocity of efflux of water (in m/s) through a small hole on the side wall of the cylinder near its bottom is [AIEEE 2002] |
| A. | 10 |
| B. | 20 |
| C. | 25.5 |
| D. | 5 |
| Answer» C. 25.5 | |
| 6924. |
In which one of the following cases will the liquid flow in a pipe be most streamlined [Pb. CET 2005] |
| A. | Liquid of high viscosity and high density flowing through a pipe of small radius |
| B. | Liquid of high viscosity and low density flowing through a pipe of small radius |
| C. | Liquid of low viscosity and low density flowing through a pipe of large radius |
| D. | Liquid of low viscosity and high density flowing through a pipe of large radius |
| Answer» C. Liquid of low viscosity and low density flowing through a pipe of large radius | |
| 6925. |
A large tank filled with water to a height ?h? is to be emptied through a small hole at the bottom. The ratio of time taken for the level of water to fall from h to \[\frac{h}{2}\] and from \[\frac{h}{2}\] to zero is [EAMCET (Engg.) 2003] |
| A. | \[\sqrt{2}\] |
| B. | \[\frac{1}{\sqrt{2}}\] |
| C. | \[\sqrt{2}-1\] |
| D. | \[\frac{1}{\sqrt{2}-1}\] |
| Answer» D. \[\frac{1}{\sqrt{2}-1}\] | |
| 6926. |
A system is given 300 calories of heat and it does 600 joules of work. How much does the internal energy of the system change in this process (J = 4.18 joules/cal) [MP PET 1991] |
| A. | 654 Joule |
| B. | 156.5 Joule |
| C. | ? 300 Joule |
| D. | ? 528.2 Joule |
| Answer» B. 156.5 Joule | |
| 6927. |
If the amount of heat given to a system be 35 joules and the amount of work done by the system be \[-15\]joules, then the change in the internal energy of the system is [MP PMT 1989] |
| A. | \[-50\] joules |
| B. | 20 joules |
| C. | 30 joules |
| D. | 50 joules |
| Answer» E. | |
| 6928. |
The temperature of an ideal gas is kept constant as it expands. The gas does external work. During this process, the internal energy of the gas [MP PMT 1990] |
| A. | Decreases |
| B. | Increases |
| C. | Remains constant |
| D. | Depends on the molecular motion |
| Answer» D. Depends on the molecular motion | |
| 6929. |
A thermodynamic system goes from states (i) \[{{P}_{1}}\], V to \[2{{P}_{1}}\], V (ii) P, V to P, 2V. Then work done in the two cases is [MP PMT 1990] |
| A. | Zero, Zero |
| B. | Zero, \[P{{V}_{1}}\] |
| C. | \[P{{V}_{1}}\], Zero |
| D. | \[P{{V}_{1}},\ {{P}_{1}}{{V}_{1}}\] |
| Answer» C. \[P{{V}_{1}}\], Zero | |
| 6930. |
Which of the following is incorrect regarding the first law of thermodynamics [AIEEE 2005] |
| A. | It introduces the concept of the internal energy |
| B. | It introduces the concept of the entropy |
| C. | It is not applicable to any cyclic process |
| D. | None of the above |
| Answer» C. It is not applicable to any cyclic process | |
| 6931. |
If a system undergoes contraction of volume then the work done by the system will be [BHU 1999] |
| A. | Zero |
| B. | Negligible |
| C. | Negative |
| D. | Positive |
| Answer» D. Positive | |
| 6932. |
A perfect gas goes from state A to another state B by absorbing \[8\times {{10}^{5}}J\] of heat and doing \[6.5\times {{10}^{5}}J\] of external work. It is now transferred between the same two states in another process in which it absorbs \[{{10}^{5}}J\] of heat. Then in the second process [BHU 1997] |
| A. | Work done on the gas is \[0.5\times {{10}^{5}}J\] |
| B. | Work done by gas is \[0.5\times {{10}^{5}}J\] |
| C. | Work done on gas is \[{{10}^{5}}J\] |
| D. | Work done by gas is \[{{10}^{5}}J\] |
| Answer» B. Work done by gas is \[0.5\times {{10}^{5}}J\] | |
| 6933. |
The state of a thermodynamic system is represented by [MH CET 2004] |
| A. | Pressure only |
| B. | Volume only |
| C. | Pressure, volume and temperature |
| D. | Number of moles |
| Answer» D. Number of moles | |
| 6934. |
A monoatomic gas of n-moles is heated from temperature T1 to T2 under two different conditions (i) at constant volume and (ii) at constant pressure. The change in internal energy of the gas is [CPMT 2000] |
| A. | More for (i) |
| B. | More for (ii) |
| C. | Same in both cases |
| D. | Independent of number of moles |
| Answer» D. Independent of number of moles | |
| 6935. |
In a thermodynamics process, pressure of a fixed mass of a gas is changed in such a manner that the gas releases 20 J of heat and 8J of work is done on the gas. If the initial internal energy of the gas was 30J. The final internal energy will be [DPMT 2002] |
| A. | 18J |
| B. | 9J |
| C. | 4.5J |
| D. | 36J |
| Answer» B. 9J | |
| 6936. |
If heat given to a system is 6 kcal and work done is 6 kJ. Then change in internal energy is [BHU Med. 2000] |
| A. | 19.1 kJ |
| B. | 12.5 kJ |
| C. | 25 kJ |
| D. | Zero |
| Answer» B. 12.5 kJ | |
| 6937. |
When heat energy of 1500 Joules, is supplied to a gas at constant pressure \[2.1\times {{10}^{5}}N/{{m}^{2}}\], there was an increase in its volume equal to \[2.5\times {{10}^{-3}}{{m}^{3}}\]. The increase in internal energy of the gas in Joules is [EAMCET (Engg.) 1999] |
| A. | 450 |
| B. | 525 |
| C. | 975 |
| D. | 2025 |
| Answer» D. 2025 | |
| 6938. |
Temperature is a measurement of coldness or hotness of an object. This definition is based on [RPET 2003] |
| A. | Zeroth law of thermodynamics |
| B. | First law of thermodynamics |
| C. | Second law of thermodynamics |
| D. | Newton's law of cooling |
| Answer» B. First law of thermodynamics | |
| 6939. |
Heat given to a system is 35 joules and work done by the system is 15 joules. The change in the internal energy of the system will be [MP PET/PMT 1988] |
| A. | ? 50 J |
| B. | 20 J |
| C. | 30 J |
| D. | 50 J |
| Answer» C. 30 J | |
| 6940. |
If \[{{C}_{V}}=4.96cal/mole\] K, then increase in internal energy when temperature of 2 moles of this gas is increased from 340 K to 342 K [RPET 1997] |
| A. | 27.80 cal |
| B. | 19.84 cal |
| C. | 13.90 cal |
| D. | 9.92 cal |
| Answer» C. 13.90 cal | |
| 6941. |
If the ratio of specific heat of a gas at constant pressure to that at constant volume is \[\gamma \], the change in internal energy of a mass of gas, when the volume changes from V to 2V constant pressure p, is [CBSE PMT 1998] |
| A. | \[R/(\gamma -1)\] |
| B. | \[pV\] |
| C. | \[pV/(\gamma -1)\] |
| D. | \[\gamma pV/(\gamma -1)\] |
| Answer» D. \[\gamma pV/(\gamma -1)\] | |
| 6942. |
One mole of an ideal monoatomic gas is heated at a constant pressure of one atmosphere from \[{{0}^{o}}C\] to \[{{100}^{o}}C\]. Then the change in the internal energy is [Pb. PMT 2001] |
| A. | 6.56 joules |
| B. | \[8.32\times {{10}^{2}}\]joules |
| C. | \[12.48\times {{10}^{2}}\]joules |
| D. | 20.80 joules |
| Answer» D. 20.80 joules | |
| 6943. |
Out of the following which quantity does not depend on path [RPET 2002] |
| A. | Temperature |
| B. | Energy |
| C. | Work |
| D. | None of these |
| Answer» B. Energy | |
| 6944. |
First law of thermodynamics is a special case of [CPMT 1985; RPET 2000; DCE 2000; CBSE PMT 2000; AIEEE 2002; AFMC 2002] |
| A. | Newton's law |
| B. | Law of conservation of energy |
| C. | Charle's law |
| D. | Law of heat exchange |
| Answer» C. Charle's law | |
| 6945. |
Heat is not being exchanged in a body. If its internal energy is increased, then [RPMT 2002] |
| A. | Its temperature will increase |
| B. | Its temperature will decrease |
| C. | Its temperature will remain constant |
| D. | None of these |
| Answer» B. Its temperature will decrease | |
| 6946. |
In a thermodynamic process, pressure of a fixed mass of a gas is changed in such a manner that the gas molecules gives out 20 J of heat and 10 J of work is done on the gas. If the initial internal energy of the gas was 40 J, then the final internal energy will be [DPMT 2004] |
| A. | 30 J |
| B. | 20 J |
| C. | 60 J |
| D. | 40 J |
| Answer» D. 40 J | |
| 6947. |
A system is provided with 200 cal of heat and the work done by the system on the surrounding is 40 J. Then its internal energy [Orissa PMT 2004] |
| A. | Increases by 600 J |
| B. | Decreases by 800 J |
| C. | Increases by 800 J |
| D. | Decreases by 50 J |
| Answer» D. Decreases by 50 J | |
| 6948. |
Which of the following statements is correct for any thermodynamic system [AIEEE 2004] |
| A. | The internal energy changes in all processes |
| B. | Internal energy and entropy are state functions |
| C. | The change in entropy can never be zero |
| D. | The work done in an adiabatic process is always zero |
| Answer» C. The change in entropy can never be zero | |
| 6949. |
In a thermodynamic system working substance is ideal gas, its internal energy is in the form of [MP PMT 2003] |
| A. | Kinetic energy only |
| B. | Kinetic and potential energy |
| C. | Potential energy |
| D. | None of these |
| Answer» B. Kinetic and potential energy | |
| 6950. |
In changing the state of thermodynamics from A to B state, the heat required is Q and the work done by the system is W. The change in its internal energy is [MP PMT 1986; AMU (Med.) 2001] |
| A. | Q + W |
| B. | Q ? W |
| C. | Q |
| D. | \[\frac{Q-W}{2}\] |
| Answer» C. Q | |