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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.
| 6851. |
Four wires each of length 2.0 metres are bent into four loops P, Q, R and S and then suspended into uniform magnetic field. Same current is passed in each loop. Which statement is correct [MP PET 1995; DPMT 1999] |
| A. | Couple on loop P will be the highest |
| B. | Couple on loop Q will be the highest |
| C. | Couple on loop R will be the highest |
| D. | Couple on loop S will be the highest |
| Answer» E. | |
| 6852. |
An electron moves with a constant speed v along a circle of radius r. Its magnetic moment will be (e is the electron's charge) [MP PMT 1994] |
| A. | evr |
| B. | \[\frac{1}{2}evr\] |
| C. | \[\pi {{r}^{2}}ev\] |
| D. | \[2\pi rev\] |
| Answer» C. \[\pi {{r}^{2}}ev\] | |
| 6853. |
A rectangular loop carrying a current i is placed in a uniform magnetic field B. The area enclosed by the loop is A. If there are n turns in the loop, the torque acting on the loop is given by [MP PMT 1994] |
| A. | \[ni\,\overrightarrow{A}\times \overrightarrow{B}\] |
| B. | \[ni\,\overrightarrow{A}\cdot \overrightarrow{B}\] |
| C. | \[\frac{1}{n}(i\overrightarrow{A}\times \overrightarrow{B})\] |
| D. | \[\frac{1}{n}(i\overrightarrow{A}\cdot \overrightarrow{B})\] |
| Answer» B. \[ni\,\overrightarrow{A}\cdot \overrightarrow{B}\] | |
| 6854. |
A current of 10 ampere is flowing in a wire of length 1.5 m. A force of 15 N acts on it when it is placed in a uniform magnetic field of 2 tesla. The angle between the magnetic field and the direction of the current is [MP PMT 1994] |
| A. | \[30{}^\circ \] |
| B. | \[45{}^\circ \] |
| C. | \[60{}^\circ \] |
| D. | \[90{}^\circ \] |
| Answer» B. \[45{}^\circ \] | |
| 6855. |
A small coil of N turns has area A and a current I flows through it. The magnetic dipole moment of this coil will be [MP PMT 1994] |
| A. | \[NI/A\] |
| B. | \[N{{I}^{2}}A\] |
| C. | \[{{N}^{2}}AI\] |
| D. | NIA |
| Answer» E. | |
| 6856. |
A small coil of N turns has an effective area A and carries a current I. It is suspended in a horizontal magnetic field \[\overrightarrow{B}\] such that its plane is perpendicular to \[\overrightarrow{B}\]. The work done in rotating it by \[180{}^\circ \] about the vertical axis is [MP PMT 1994] |
| A. | NAIB |
| B. | 2NAIB |
| C. | \[2\pi NAIB\] |
| D. | \[4\pi NAIB\] |
| Answer» C. \[2\pi NAIB\] | |
| 6857. |
A moving coil galvanometer has N number of turns in a coil of effective area A, it carries a current I. The magnetic field B is radial. The torque acting on the coil is [MP PMT 1994] |
| A. | \[N{{A}^{2}}{{B}^{2}}I\] |
| B. | \[NAB{{I}^{2}}\] |
| C. | \[{{N}^{2}}ABI\] |
| D. | NABI |
| Answer» E. | |
| 6858. |
A rectangular loop carrying a current i is situated near a long straight wire such that the wire is parallel to the one of the sides of the loop and is in the plane of the loop. If a steady current I is established in wire as shown in figure, the loop will [IIT 1985; MP PET 1995; MP PMT 1995, 99; AIIMS 2003] |
| A. | Rotate about an axis parallel to the wire |
| B. | Move away from the wire or towards right |
| C. | Move towards the wire |
| D. | Remain stationary |
| Answer» D. Remain stationary | |
| 6859. |
In a moving coil galvanometer, the deflection of the coil \[\theta \] is related to the electrical current i by the relation [MP PMT 1996, 2000, 03; RPMT 1997; CPMT 1975; MP PET 1999] |
| A. | \[i\propto \tan \theta \] |
| B. | \[i\propto \theta \] |
| C. | \[i\propto {{\theta }^{2}}\] |
| D. | \[i\propto \sqrt{\theta }\] |
| Answer» C. \[i\propto {{\theta }^{2}}\] | |
| 6860. |
The unit of electric current ?ampere? is the current which when flowing through each of two parallel wires spaced 1 m apart in vacuum and of infinite length will give rise to a force between them equal to [BIT 1987; CBSE PMT1998; MP PET 1999; MP PMT 2002] |
| A. | \[1\,N/m\] |
| B. | \[2\times {{10}^{-7}}\,N/m\] |
| C. | \[1\times {{10}^{-2}}\,N/m\] |
| D. | \[4\pi \times {{10}^{-7}}\,N/m\] |
| Answer» C. \[1\times {{10}^{-2}}\,N/m\] | |
| 6861. |
A moving coil sensitive galvanometer gives at once much more deflection. To control its speed of deflection [MP PET 1985] |
| A. | A high resistance is to be connected across its terminals |
| B. | A magnet should be placed near the coil |
| C. | A small copper wire should be connected across its terminals |
| D. | The body of galvanometer should be earthed |
| Answer» C. A small copper wire should be connected across its terminals | |
| 6862. |
The deflection in a moving coil galvanometer is [MP PMT 1993] |
| A. | Directly proportional to the torsional constant |
| B. | Directly proportional to the number of turns in the coil |
| C. | Inversely proportional to the area of the coil |
| D. | Inversely proportional to the current flowing |
| Answer» C. Inversely proportional to the area of the coil | |
| 6863. |
The radius of a circular loop is r and a current i is flowing in it. The equivalent magnetic moment will be [CPMT 1990] |
| A. | ir |
| B. | \[2\pi ir\] |
| C. | \[i\pi {{r}^{2}}\] |
| D. | \[\frac{1}{{{r}^{2}}}\] |
| Answer» D. \[\frac{1}{{{r}^{2}}}\] | |
| 6864. |
To make the field radial in a moving coil galvanometer [MP PET 1993] |
| A. | The number of turns in the coil is increased |
| B. | Magnet is taken in the form of horse-shoe |
| C. | Poles are cylindrically cut |
| D. | Coil is wounded on aluminium frame |
| Answer» D. Coil is wounded on aluminium frame | |
| 6865. |
A current carrying loop is placed in a uniform magnetic field. The torque acting on it does not depend upon [CPMT 1985; RPMT 1997; Kerala PMT 2002] |
| A. | Shape of the loop |
| B. | Area of the loop |
| C. | Value of the current |
| D. | Magnetic field |
| Answer» B. Area of the loop | |
| 6866. |
3 A of current is flowing in a linear conductor having a length of 40 cm. The conductor is placed in a magnetic field of strength 500 gauss and makes an angle of \[30{}^\circ \] with the direction of the field. It experiences a force of magnitude [MP PET 1993] |
| A. | \[3\times {{10}^{4}}\,newton\] |
| B. | \[3\times {{10}^{2}}\,newton\] |
| C. | \[3\times {{10}^{-2}}\,newton\] |
| D. | \[3\times {{10}^{-4}}\,newton\] |
| Answer» D. \[3\times {{10}^{-4}}\,newton\] | |
| 6867. |
A circular coil of radius 4 cm has 50 turns. In this coil a current of 2 A is flowing. It is placed in a magnetic field of 0.1 \[weber/{{m}^{2}}\]. The amount of work done in rotating it through \[180{}^\circ \] from its equilibrium position will be [CPMT 1977] |
| A. | 0.1 J |
| B. | 0.2 J |
| C. | 0.4 J |
| D. | 0.8 J |
| Answer» B. 0.2 J | |
| 6868. |
Two free parallel wires carrying currents in opposite direction [CPMT 1977; MP PMT 1993; AFMC 2002; CPMT 2003] |
| A. | Attract each other |
| B. | Repel each other |
| C. | Neither attract nor repel |
| D. | Get rotated to be perpendicular to each other |
| Answer» C. Neither attract nor repel | |
| 6869. |
Two long and parallel wires are at a distance of 0.1 m and a current of 5 A is flowing in each of these wires. The force per unit length due to these wires will be [CPMT 1977] |
| A. | \[5\times {{10}^{-5}}\,N/m\] |
| B. | \[5\times {{10}^{-3}}\,N/m\] |
| C. | \[2.5\times {{10}^{-5}}\,N/m\] |
| D. | \[2.5\times {{10}^{-4}}\,N/m\] |
| Answer» B. \[5\times {{10}^{-3}}\,N/m\] | |
| 6870. |
Air is streaming past a horizontal air plane wing such that its speed in 120 m/s over the upper surface and 90 m/s at the lower surface. If the density of air is 1.3 kg per metre3 and the wing is 10 m long and has an average width of 2 m, then the difference of the pressure on the two sides of the wing of |
| A. | 4095.0 Pascal |
| B. | 409.50 Pascal |
| C. | 40.950 Pascal |
| D. | 4.0950 Pascal |
| Answer» B. 409.50 Pascal | |
| 6871. |
A manometer connected to a closed tap reads 3.5 × 105 N/m2. When the valve is opened, the reading of manometer falls to 3.0 × 105 N/m2, then velocity of flow of water is |
| A. | 100 m/s |
| B. | 10 m/s |
| C. | 1 m/s |
| D. | \[10\sqrt{10}\] m/s |
| Answer» C. 1 m/s | |
| 6872. |
In the following fig. is shown the flow of liquid through a horizontal pipe. Three tubes A, B and C are connected to the pipe. The radii of the tubes A, B and C at the junction are respectively 2 cm, 1 cm and 2 cm. It can be said that the |
| A. | Height of the liquid in the tube A is maximum |
| B. | Height of the liquid in the tubes A and B is the same |
| C. | Height of the liquid in all the three tubes is the same |
| D. | Height of the liquid in the tubes A and C is the same |
| Answer» E. | |
| 6873. |
An incompressible fluid flows steadily through a cylindrical pipe which has radius 2r at point A and radius r at B further along the flow direction. If the velocity at point A is v, its velocity at point B is [Kerala PMT 2005] |
| A. | 2v |
| B. | v |
| C. | v/2 |
| D. | 4v |
| Answer» E. | |
| 6874. |
Consider the following equation of Bernouilli?s theorem. \[P+\frac{1}{2}\rho {{V}^{2}}+\rho gh=K\](constant) The dimensions of K/P are same as that of which of the following [AFMC 2005] |
| A. | Thrust |
| B. | Pressure |
| C. | Angle |
| D. | Viscosity |
| Answer» D. Viscosity | |
| 6875. |
What is the velocity v of a metallic ball of radius r falling in a tank of liquid at the instant when its acceleration is one-half that of a freely falling body ? (The densities of metal and of liquid are r and s respectively, and the viscosity of the liquid is h). [Kerala PET 2005] |
| A. | \[\frac{{{r}^{2}}g}{9\eta }(\rho -2\sigma )\] |
| B. | \[\frac{{{r}^{2}}g}{9\eta }(2\rho -\sigma )\] |
| C. | \[\frac{{{r}^{2}}g}{9\eta }(\rho -\sigma )\] |
| D. | \[\frac{2{{r}^{2}}g}{9\eta }(\rho -\sigma )\] |
| Answer» D. \[\frac{2{{r}^{2}}g}{9\eta }(\rho -\sigma )\] | |
| 6876. |
A manometer connected to a closed tap reads \[4.5\times {{10}^{5}}\] pascal. When the tap is opened the reading of the manometer falls to \[4\times {{10}^{5}}\] pascal. Then the velocity of flow of water is [Kerla PET 2005] |
| A. | 7 \[m{{s}^{-1}}\] |
| B. | 8 \[m{{s}^{-1}}\] |
| C. | 9 \[m{{s}^{-1}}\] |
| D. | 10 \[m{{s}^{-1}}\] |
| Answer» E. | |
| 6877. |
Water falls from a tap, down the streamline [Orissa JEE 2005] |
| A. | Area decreases |
| B. | Area increases |
| C. | Velocity remains same |
| D. | Area remains same |
| Answer» B. Area increases | |
| 6878. |
When a body falls in air, the resistance of air depends to a great extent on the shape of the body, 3 different shapes are given. Identify the combination of air resistances which truly represents the physical situation. (The cross sectional areas are the same). [KCET 2005] |
| A. | 1 < 2 < 3 |
| B. | 2 < 3 < 1 |
| C. | 3 < 2 < 1 |
| D. | 3 < 1 < 2 |
| Answer» D. 3 < 1 < 2 | |
| 6879. |
Two capillary of length L and 2L and of radius R and 2R are connected in series. The net rate of flow of fluid through them will be (given rate of the flow through single capillary, \[X=\pi P{{R}^{4}}/8\eta L)\] [DCE 2005] |
| A. | \[\frac{8}{9}X\] |
| B. | \[\frac{9}{8}X\] |
| C. | \[\frac{5}{7}X\] |
| D. | \[\frac{7}{5}X\] |
| Answer» B. \[\frac{9}{8}X\] | |
| 6880. |
The velocity of kerosene oil in a horizontal pipe is 5 m/s. If \[g=10m/{{s}^{2}}\] then the velocity head of oil will be |
| A. | 1.25 m |
| B. | 12.5 m |
| C. | 0.125 m |
| D. | 125 m |
| Answer» B. 12.5 m | |
| 6881. |
Water is flowing in a pipe of diameter 4 cm with a velocity 3 m/s. The water then enters into a tube of diameter 2 cm. The velocity of water in the other pipe is [BCECE 2005] |
| A. | 3 m/s |
| B. | 6 m/s |
| C. | 12 m/s |
| D. | 8 m/s |
| Answer» D. 8 m/s | |
| 6882. |
Two capillary tubes of the same length but different radii r1 and r2 are fitted in parallel to the bottom of a vessel. The pressure head is P. What should be the radius of a single tube that can replace the two tubes so that the rate of flow is same as before |
| A. | \[{{r}_{1}}+{{r}_{2}}\] |
| B. | \[r_{1}^{2}+r_{2}^{2}\] |
| C. | \[r_{1}^{4}+r_{2}^{4}\] |
| D. | None of these |
| Answer» E. | |
| 6883. |
A viscous fluid is flowing through a cylindrical tube. The velocity distribution of the fluid is best represented by the diagram [BCECE 2005] |
| A. | |
| B. | |
| C. | |
| D. | None of these |
| Answer» D. None of these | |
| 6884. |
Two capillaries of same length and radii in the ratio 1 : 2 are connected in series. A liquid flows through them in streamlined condition. If the pressure across the two extreme ends of the combination is 1 m of water, the pressure difference across first capillary is |
| A. | 9.4 m |
| B. | 4.9 m |
| C. | 0.49 m |
| D. | 0.94 m |
| Answer» E. | |
| 6885. |
In Poiseuilli's method of determination of coefficient of viscosity, the physical quantity that requires greater accuracy in measurement is [EAMCET 2001] |
| A. | Pressure difference |
| B. | Volume of the liquid collected |
| C. | Length of the capillary tube |
| D. | Inner radius of the capillary tube |
| Answer» E. | |
| 6886. |
The rate of flow of liquid in a tube of radius r, length l, whose ends are maintained at a pressure difference P is \[V=\frac{\pi QP\,{{r}^{4}}}{\eta l}\] where \[\eta \] is coefficient of the viscosity and Q is [DCE 2002] |
| A. | 8 |
| B. | \[\frac{1}{8}\] |
| C. | 16 |
| D. | \[\frac{1}{16}\] |
| Answer» C. 16 | |
| 6887. |
A small drop of water falls from rest through a large height h in air; the final velocity is |
| A. | \[\propto \,\sqrt{h}\] |
| B. | \[\propto \,h\] |
| C. | \[\propto \,(1/h)\] |
| D. | Almost independent of h |
| Answer» E. | |
| 6888. |
A good lubricant should have |
| A. | High viscosity |
| B. | Low viscosity |
| C. | Moderate viscosity |
| D. | High density |
| Answer» B. Low viscosity | |
| 6889. |
We have three beakers A, B and C containing glycerine, water and kerosene respectively. They are stirred vigorously and placed on a table. The liquid which comes to rest at the earliest is |
| A. | Glycerine |
| B. | Water |
| C. | Kerosene |
| D. | All of them at the same time |
| Answer» B. Water | |
| 6890. |
As the temperature of water increases, its viscosity |
| A. | Remains unchanged |
| B. | Decreases |
| C. | Increases |
| D. | Increases or decreases depending on the external pressure |
| Answer» C. Increases | |
| 6891. |
Velocity of water in a river is [CBSE PMT 1988] |
| A. | Same everywhere |
| B. | More in the middle and less near its banks |
| C. | Less in the middle and more near its banks |
| D. | Increase from one bank to other bank |
| Answer» C. Less in the middle and more near its banks | |
| 6892. |
A large tank is filled with water to a height H. A small hole is made at the base of the tank. It takes \[{{T}_{1}}\] time to decrease the height of water to \[\frac{H}{\eta }\,(\eta >1)\]; and it takes \[{{T}_{2}}\] time to take out the rest of water. If \[{{T}_{1}}={{T}_{2}}\], then the value of \[\eta \] is |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | \[2\sqrt{2}\] |
| Answer» D. \[2\sqrt{2}\] | |
| 6893. |
A streamlined body falls through air from a height h on the surface of a liquid. If d and D(D > d) represents the densities of the material of the body and liquid respectively, then the time after which the body will be instantaneously at rest, is |
| A. | \[\sqrt{\frac{2h}{g}}\] |
| B. | \[\sqrt{\frac{2h}{g}\,.\,\frac{D}{d}}\] |
| C. | \[\sqrt{\frac{2h}{g}\,.\,\frac{d}{D}}\] |
| D. | \[\sqrt{\frac{2h}{g}}\,\left( \frac{d}{D-d} \right)\] |
| Answer» E. | |
| 6894. |
A cylindrical vessel of 90 cm height is kept filled upto the brim. It has four holes 1, 2, 3, 4 which are respectively at heights of 20 cm, 30 cm, 45 cm and 50 cm from the horizontal floor PQ. The water falling at the maximum horizontal distance from the vessel comes from [CPMT 1989] |
| A. | Hole number 4 |
| B. | Hole number 3 |
| C. | Hole number 2 |
| D. | Hole number 1 |
| Answer» C. Hole number 2 | |
| 6895. |
A tank is filled with water up to a height H. Water is allowed to come out of a hole P in one of the walls at a depth D below the surface of water. Express the horizontal distance x in terms of H and D [MNR 1992; CPMT 2004] |
| A. | \[x=\sqrt{D(H-D)}\] |
| B. | \[x=\sqrt{\frac{D(H-D)}{2}}\] |
| C. | \[x=2\sqrt{D(H-D)}\] |
| D. | \[x=4\sqrt{D(H-D)}\] |
| Answer» D. \[x=4\sqrt{D(H-D)}\] | |
| 6896. |
An L-shaped glass tube is just immersed in flowing water such that its opening is pointing against flowing water. If the speed of water current is v, then |
| A. | The water in the tube rises to height \[\frac{{{v}^{2}}}{2g}\] |
| B. | The water in the tube rises to height \[\frac{g}{2{{v}^{2}}}\] |
| C. | The water in the tube does not rise at all |
| D. | None of these |
| Answer» B. The water in the tube rises to height \[\frac{g}{2{{v}^{2}}}\] | |
| 6897. |
Water enters through end A with speed \[{{v}_{1}}\] and leaves through end B with speed \[{{v}_{2}}\] of a cylindrical tube AB. The tube is always completely filled with water. In case I tube is horizontal and in case II it is vertical with end A upwards and in case III it is vertical with end B upwards. We have \[{{v}_{1}}={{v}_{2}}\] for |
| A. | Case I |
| B. | Case II |
| C. | Case III |
| D. | Each case |
| Answer» E. | |
| 6898. |
An L-shaped tube with a small orifice is held in a water stream as shown in fig. The upper end of the tube is 10.6 cm above the surface of water. What will be the height of the jet of water coming from the orifice? Velocity of water stream is 2.45 m/s |
| A. | Zero |
| B. | 20.0 cm |
| C. | 10.6 cm |
| D. | 40.0 cm |
| Answer» C. 10.6 cm | |
| 6899. |
A sniper fires a rifle bullet into a gasoline tank making a hole 53.0 m below the surface of gasoline. The tank was sealed at 3.10 atm. The stored gasoline has a density of 660 kgm?3. The velocity with which gasoline begins to shoot out of the hole is |
| A. | \[27.8\,m{{s}^{-1}}\] |
| B. | \[41.0\,m{{s}^{-1}}\] |
| C. | \[9.6\,m{{s}^{-1}}\] |
| D. | \[19.7\,m{{s}^{-1}}\] |
| Answer» C. \[9.6\,m{{s}^{-1}}\] | |
| 6900. |
A liquid flows through a horizontal tube. The velocities of the liquid in the two sections, which have areas of cross-section \[{{A}_{1}}\] and \[{{A}_{2}}\], are \[{{v}_{1}}\] and \[{{v}_{2}}\] respectively. The difference in the levels of the liquid in the two vertical tubes is h |
| A. | The volume of the liquid flowing through the tube in unit time is \[{{A}_{1}}{{v}_{1}}\] |
| B. | \[{{v}_{2}}-{{v}_{1}}=\sqrt{2gh}\] |
| C. | \[v_{2}^{2}-v_{1}^{2}=2gh\] |
| D. | The energy per unit mass of the liquid is the same in both sections of the tube |
| Answer» D. The energy per unit mass of the liquid is the same in both sections of the tube | |