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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.
| 8651. |
A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the particle. The motion of the particle takes place in a plane. It follows that [IIT 1987] |
| A. | Velocity is constant |
| B. | Acceleration is constant |
| C. | Kinetic energy is constant |
| D. | It moves in a circular path |
| Answer» D. It moves in a circular path | |
| 8652. |
A ray of light of intensity I is incident on a parallel glass-slab at a point A as shown in fig. It undergoes partial reflection and refraction. At each reflection 25% of incident energy is reflected. The rays AB and A'B' undergo interference. The ratio \[{{I}_{\max }}/{{I}_{\min }}\] is [IIT 1990] |
| A. | 4 : 1 |
| B. | 8 : 1 |
| C. | 7 : 1 |
| D. | 49 : 1 |
| Answer» E. | |
| 8653. |
A thin slice is cut out of a glass cylinder along a plane parallel to its axis. The slice is placed on a flat glass plate as shown. The observed interference fringes from this combination shall be [IIT-JEE (Screening)1999] |
| A. | Straight |
| B. | Circular |
| C. | Equally spaced |
| D. | Having fringe spacing which increases as we go outwards |
| Answer» B. Circular | |
| 8654. |
Two plane mirrors. A and B are aligned parallel to each other, as shown in the figure. A light ray is incident at an angle of \[30{}^\circ \] at a point just inside one end of A. The plane of incidence coincides with the plane of the figure. The maximum number of times the ray undergoes reflections (including the first one) before it emerges out is [IIT-JEE (Screening) 2002] |
| A. | 28 |
| B. | 30 |
| C. | 32 |
| D. | 34 |
| Answer» C. 32 | |
| 8655. |
A point source of light B is placed at a distance L in front of the centre of a mirror of width d hung vertically on a wall. A man walks in front of the mirror along a line parallel to the mirror at a distance 2L from it as shown. The greatest distance over which he can see the image of the light source in the mirror is [IIT-JEE (Screening) 2000] |
| A. | d/2 |
| B. | d |
| C. | 2d |
| D. | 3d |
| Answer» E. | |
| 8656. |
A silicon speciman is made into a P-type semi-conductor by dopping, on an average, one Indium atom per \[5\times {{10}^{7}}\]silicon atoms. If the number density of atoms in the silicon specimen is \[5\times {{10}^{28}}\text{atoms}/{{m}^{3}}\] then the number of acceptor atoms in silicon per cubic centimetre will be [MP PMT 1993, 2003] |
| A. | \[2.5\times {{10}^{30}}atoms/c{{m}^{3}}\] |
| B. | \[1.0\times {{10}^{13}}atoms/c{{m}^{3}}\] |
| C. | \[1.0\times {{10}^{15}}atoms/c{{m}^{3}}\] |
| D. | \[2.5\times {{10}^{36}}atoms/c{{m}^{3}}\] |
| Answer» D. \[2.5\times {{10}^{36}}atoms/c{{m}^{3}}\] | |
| 8657. |
A sky wave with a frequency 55 MHz is incident on D-region of earth's atmosphere at 45o. The angle of refraction is (electron density for D-region is 400 electron/cm3) [Haryana PMT 2003] |
| A. | 60° |
| B. | 45° |
| C. | 30° |
| D. | 15° |
| Answer» C. 30° | |
| 8658. |
An a-particle of 5 MeV energy strikes with a nucleus of uranium at stationary at an scattering angle of 180o. The nearest distance upto which a-particle reaches the nucleus will be of the order of [IIT 1981; AIEEE 2004] |
| A. | \[1\,\overset{o}{\mathop{A}}\,\] |
| B. | \[{{10}^{-10}}cm\] |
| C. | \[{{10}^{-12}}cm\] |
| D. | \[{{10}^{-15}}cm\] |
| Answer» D. \[{{10}^{-15}}cm\] | |
| 8659. |
A 1mA beam of protons with a cross-sectional area of 0.5 sq. mm is moving with a velocity of \[3\times {{10}^{4}}m{{s}^{-1}}\]. Then charge density of beam is [CPMT 2002] |
| A. | \[6.6\times {{10}^{-4}}C/{{m}^{3}}\] |
| B. | \[6.6\times {{10}^{-5}}C/{{m}^{3}}\] |
| C. | \[6.6\times {{10}^{-6}}C/{{m}^{3}}\] |
| D. | None of these |
| Answer» C. \[6.6\times {{10}^{-6}}C/{{m}^{3}}\] | |
| 8660. |
When 100 volts dc is supplied across a solenoid, a current of 1.0 amperes flows in it. When 100 volts ac is applied across the same coil, the current drops to 0.5 ampere. If the frequency of ac source is 50 Hz, then the impedance and inductance of the solenoid are [CPMT 1990] |
| A. | 200 W and 0.55 henry |
| B. | 100 W and 0.86 henry |
| C. | 200 W and 1.0 henry |
| D. | 100 W and 0.93 henry |
| Answer» B. 100 W and 0.86 henry | |
| 8661. |
An electron moves along the line AB, which lies in the same plane as a circular loop of conducting wires as shown in the diagram. What will be the direction of current induced if any, in the loop [MP PET 1989; AIIMS 1982, 2001; KCET 2003; UPSEAT 2005] |
| A. | No current will be induced |
| B. | The current will be clockwise |
| C. | The current will be anticlockwise |
| D. | The current will change direction as the electron passes by |
| Answer» E. | |
| 8662. |
Two identical magnetic dipoles of magnetic moments 1.0 A-m2 each, placed at a separation of 2m with their axis perpendicular to each other. The resultant magnetic field at a point midway between the dipoles is [Roorkee 1995] |
| A. | \[5\times {{10}^{-7}}T\] |
| B. | \[\sqrt{5}\times {{10}^{-7}}T\] |
| C. | \[{{10}^{-7}}T\] |
| D. | None of these |
| Answer» C. \[{{10}^{-7}}T\] | |
| 8663. |
The resistance of the filament of an electric bulb changes with temperature. If an electric bulb rated 220 volt and 100 watt is connected \[(220\times .8)\] volt sources, then the actual power would be [CPMT 1989] |
| A. | \[100\times 0.8\,watt\] |
| B. | \[100\times {{(0.8)}^{2}}watt\] |
| C. | Between \[100\times 0.8\]watt and 100 watt |
| D. | Between \[100\times {{(0.8)}^{2}}watt\] and \[100\times 0.8\]watt |
| Answer» E. | |
| 8664. |
The (x, y) coordinates of the corners of a square plate are (0, 0), (L, 0), (L, L) and (0, L). The edges of the plate are clamped and transverse standing waves are set up in it. If u(x, y) denotes the displacement of the plate at the point (x, y) at some instant of time, the possible expression(s) for u is(are) (a = positive constant) [IIT 1998; Orissa PMT 2004] |
| A. | \[a\cos \frac{\pi x}{2L}\cos \frac{\pi y}{2L}\] |
| B. | \[a\sin \frac{\pi x}{L}\sin \frac{\pi y}{L}\] |
| C. | \[a\sin \frac{\pi x}{L}\sin \frac{2\pi y}{L}\] |
| D. | \[a\cos \frac{2\pi x}{L}\cos \frac{\pi y}{L}\] |
| Answer» C. \[a\sin \frac{\pi x}{L}\sin \frac{2\pi y}{L}\] | |
| 8665. |
A wave disturbance in a medium is described by \[y(x,\,t)=0.02\cos \,\left( 50\,\pi t+\frac{\pi }{2} \right)\cos (10\pi x)\], where x and y are in metres and t in seconds [IIT 1995] |
| A. | A displacement node occurs at x = 0.15 m |
| B. | An antinode occurs at x = 0.3 m |
| C. | The wavelength of the wave is 0.2 m |
| D. | The speed of the wave is 5.0 m/s |
| Answer» B. An antinode occurs at x = 0.3 m | |
| 8666. |
The displacement of a particle varies with time as \[x=12\sin \omega t-16{{\sin }^{3}}\omega t\](in cm). If its motion is S.H.M., then its maximum acceleration is |
| A. | \[12\,{{\omega }^{2}}\] |
| B. | \[36\,{{\omega }^{2}}\] |
| C. | \[144\,{{\omega }^{2}}\] |
| D. | \[\sqrt{192}\,{{\omega }^{2}}\] |
| Answer» C. \[144\,{{\omega }^{2}}\] | |
| 8667. |
Two particles executes S.H.M. of same amplitude and frequency along the same straight line. They pass one another when going in opposite directions, and each time their displacement is half of their amplitude. The phase difference between them is [MP PMT 1999] |
| A. | 30° |
| B. | 60° |
| C. | 90° |
| D. | 120° |
| Answer» E. | |
| 8668. |
Two rods (one semi-circular and other straight) of same material and of same cross-sectional area are joined as shown in the figure. The points A and B are maintained at different temperature. The ratio of the heat transferred through a cross-section of a semi-circular rod to the heat transferred through a cross section of the straight rod in a given time is [UPSEAT 2002] |
| A. | 2 : p |
| B. | 1 : 2 |
| C. | p : 2 |
| D. | 3 : 2 |
| Answer» B. 1 : 2 | |
| 8669. |
When an ideal diatomic gas is heated at constant pressure, the fraction of the heat energy supplied which increases the internal energy of the gas, is [IIT 1990; UPSEAT 1998; RPET 2000] |
| A. | \[\frac{2}{5}\] |
| B. | \[\frac{3}{5}\] |
| C. | \[\frac{3}{7}\] |
| D. | \[\frac{5}{7}\] |
| Answer» E. | |
| 8670. |
In an electrical cable there is a single wire of radius 9 mm of copper. Its resistance is \[5\,\Omega \]. The cable is replaced by 6 different insulated copper wires, the radius of each wire is \[3\,mm\]. Now the total resistance of the cable will be [CPMT 1988] |
| A. | \[7.5\,\Omega \] |
| B. | \[45\,\Omega \] |
| C. | \[90\,\Omega \] |
| D. | \[270\,\Omega \] |
| Answer» B. \[45\,\Omega \] | |
| 8671. |
A glass flask is filled up to a mark with 50 cc of mercury at 18ºC. If the flask and contents are heated to 38ºC, how much mercury will be above the mark? (a for glass is 9 × 10?6/ºC and coefficient of real expansion of mercury is 180 × 10?6/ºC) [EAMCET 1997] |
| A. | 0.85 cc |
| B. | 0.46 cc |
| C. | 0.153 cc |
| D. | 0.05 cc |
| Answer» D. 0.05 cc | |
| 8672. |
A U-tube in which the cross-sectional area of the limb on the left is one quarter, the limb on the right contains mercury (density 13.6 g/cm3). The level of mercury in the narrow limb is at a distance of 36 cm from the upper end of the tube. What will be the rise in the level of mercury in the right limb if the left limb is filled to the top with water |
| A. | 1.2 cm |
| B. | 2.35 cm |
| C. | 0.56 cm |
| D. | 0.8 cm |
| Answer» D. 0.8 cm | |
| 8673. |
If a vector \[\overrightarrow{P}\] making angles a, b, and g respectively with the X, Y and Z axes respectively. Then \[{{\sin }^{2}}\alpha +{{\sin }^{2}}\beta +{{\sin }^{2}}\gamma =\] |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» D. 3 | |
| 8674. |
Two equal negative charge ? q are fixed at the fixed points \[(0,\,a)\] and \[(0,\,-a)\] on the Y-axis. A positive charge Q is released from rest at the point \[(2a,\,0)\] on the X-axis. The charge Q will [IIT 1984; Bihar MEE 1995; MP PMT 1996] |
| A. | Execute simple harmonic motion about the origin |
| B. | Move to the origin and remain at rest |
| C. | Move to infinity |
| D. | Execute oscillatory but not simple harmonic motion |
| Answer» E. | |
| 8675. |
There is a horizontal film of soap solution. On it a thread is placed in the form of a loop. The film is pierced inside the loop and the thread becomes a circular loop of radius R. If the surface tension of the loop be T, then what will be the tension in the thread [RPET 1996] |
| A. | \[\pi {{R}^{2}}/T\] |
| B. | \[\pi {{R}^{2}}T\] |
| C. | \[2\pi RT\] |
| D. | \[2RT\] |
| Answer» E. | |
| 8676. |
A block of mass 2 kg rests on a rough inclined plane making an angle of 30° with the horizontal. The coefficient of static friction between the block and the plane is 0.7. The frictional force on the block is [IIT 1980; J & K CET 2004] |
| A. | 9.8 N |
| B. | \[0.7\times 9.8\times \sqrt{3}\,N\] |
| C. | \[9.8\times \sqrt{3}\,N\] |
| D. | \[0.8\times 9.8\,N\] |
| Answer» B. \[0.7\times 9.8\times \sqrt{3}\,N\] | |
| 8677. |
Consider the following statement: When jumping from some height, you should bend your knees as you come to rest, instead of keeping your legs stiff. Which of the following relations can be useful in explaining the statement [AMU (Engg.) 2001] |
| A. | \[\Delta \overrightarrow{{{P}_{1}}}=-\Delta \overrightarrow{{{P}_{2}}}\] |
| B. | \[\Delta E=-\Delta (PE+KE)=0\] |
| C. | \[\overrightarrow{F}\Delta t=m\Delta \overrightarrow{v}\] |
| D. | \[\Delta \overrightarrow{x}\propto \Delta \overrightarrow{F}\] Where symbols have their usual meaning |
| Answer» D. \[\Delta \overrightarrow{x}\propto \Delta \overrightarrow{F}\] Where symbols have their usual meaning | |
| 8678. |
A particle is dropped vertically from rest from a height. The time taken by it to fall through successive distances of 1 m each will then be [Kurukshetra CEE 1996] |
| A. | All equal, being equal to \[\sqrt{2/g}\] second |
| B. | In the ratio of the square roots of the integers 1, 2, 3..... |
| C. | (c) In the ratio of the difference in the square roots of the integers i.e. \[\sqrt{1},\,(\sqrt{2}-\sqrt{1}),\,(\sqrt{3}-\sqrt{2}),\,(\sqrt{4}-\sqrt{3})\]... |
| D. | In the ratio of the reciprocal of the square roots of the integers i.e.,. \[\frac{1}{\sqrt{1}},\,\frac{1}{\sqrt{2}},\frac{1}{\sqrt{3}},\,\frac{1}{\sqrt{4}}\] |
| Answer» D. In the ratio of the reciprocal of the square roots of the integers i.e.,. \[\frac{1}{\sqrt{1}},\,\frac{1}{\sqrt{2}},\frac{1}{\sqrt{3}},\,\frac{1}{\sqrt{4}}\] | |
| 8679. |
A 40 kg slab rests on a frictionless floor as shown in the figure. A 10 kg block rests on the top of the slab. The static coefficient of friction between the block and slab is 0.60 while the kinetic friction is 0.40. The 10 kg block is acted upon by a horizontal force 100 N. If \[g=9.8\,m/{{s}^{2}}\], the resulting acceleration of the slab will be [NCERT 1982] |
| A. | \[0.98\,m/{{s}^{2}}\] |
| B. | \[1.47\,m/{{s}^{2}}\] |
| C. | \[1.52\,m/{{s}^{2}}\] |
| D. | \[6.1\,m/{{s}^{2}}\] |
| Answer» B. \[1.47\,m/{{s}^{2}}\] | |
| 8680. |
A ball is projected upwards from a height \[h\] above the surface of the earth with velocity \[v\]. The time at which the ball strikes the ground is |
| A. | \[\frac{v}{g}+\frac{2hg}{\sqrt{2}}\] |
| B. | \[\frac{v}{g}\left[ 1-\sqrt{1+\frac{2h}{g}} \right]\] |
| C. | \[\frac{v}{g}\left[ 1+\sqrt{1+\frac{2gh}{{{v}^{2}}}} \right]\] |
| D. | \[\frac{v}{g}\left[ 1+\sqrt{{{v}^{2}}+\frac{2g}{h}} \right]\] |
| Answer» D. \[\frac{v}{g}\left[ 1+\sqrt{{{v}^{2}}+\frac{2g}{h}} \right]\] | |
| 8681. |
A rocket is propelled by a gas which is initially at a temperature of 4000 K. The temperature of the gas falls to 1000 K as it leaves the exhaust nozzle. The gas which will acquire the largest momentum while leaving the nozzle, is [SCRA 1994] |
| A. | Hydrogen |
| B. | Helium |
| C. | Nitrogen |
| D. | Argon |
| Answer» E. | |
| 8682. |
A body of mass m rests on horizontal surface. The coefficient of friction between the body and the surface is \[\mu .\] If the mass is pulled by a force P as shown in the figure, the limiting friction between body and surface will be [BHU 2004] |
| A. | \[\mu mg\] |
| B. | \[\mu \,\left[ mg+\left( \frac{P}{2} \right) \right]\] |
| C. | \[\mu \,\left[ mg-\left( \frac{P}{2} \right) \right]\] |
| D. | \[\mu \,\left[ mg-\left( \frac{\sqrt{3}\,P}{2} \right) \right]\] |
| Answer» D. \[\mu \,\left[ mg-\left( \frac{\sqrt{3}\,P}{2} \right) \right]\] | |
| 8683. |
The spring balance A reads 2 kg with a block m suspended from it. A balance B reads 5 kg when a beaker filled with liquid is put on the pan of the balance. The two balances are now so arranged that the hanging mass is inside the liquid as shown in figure. In this situation [IIT 1985] |
| A. | The balance A will read more than 2 kg |
| B. | The balance B will read more than 5 kg |
| C. | The balance A will read less than 2 kg and B will read more than 5 kg |
| D. | The balances A and B will read 2 kg and 5 kg respectively |
| Answer» C. The balance A will read less than 2 kg and B will read more than 5 kg | |
| 8684. |
A stone dropped from a building of height \[h\] and it reaches after \[t\] seconds on earth. From the same building if two stones are thrown (one upwards and other downwards) with the same velocity u and they reach the earth surface after \[{{t}_{1}}\] and \[{{t}_{2}}\] seconds respectively, then [CPMT 1997; UPSEAT 2002; KCET 2002] |
| A. | \[t={{t}_{1}}-{{t}_{2}}\] |
| B. | \[t=\frac{{{t}_{1}}+{{t}_{2}}}{2}\] |
| C. | \[t=\sqrt{{{t}_{1}}{{t}_{2}}}\] |
| D. | \[t=t_{1}^{2}t_{2}^{2}\] |
| Answer» D. \[t=t_{1}^{2}t_{2}^{2}\] | |
| 8685. |
A block P of mass m is placed on a frictionless horizontal surface. Another block Q of same mass is kept on P and connected to the wall with the help of a spring of spring constant k as shown in the figure. \[{{\mu }_{s}}\] is the coefficient of friction between P and Q. The blocks move together performing SHM of amplitude A. The maximum value of the friction force between P and Q is [IIT-JEE (Screening) 2004] |
| A. | \[kA\] |
| B. | \[\frac{kA}{2}\] |
| C. | Zero |
| D. | \[{{\mu }_{s}}\,mg\] |
| Answer» C. Zero | |
| 8686. |
A car accelerates from rest at a constant rate \[\alpha \]for some time, after which it decelerates at a constant rate \[\beta \]and comes to rest. If the total time elapsed is t, then the maximum velocity acquired by the car is [IIT 1978; CBSE PMT 1994] |
| A. | \[\left( \frac{{{\alpha }^{2}}+{{\beta }^{2}}}{\alpha \beta } \right)\,t\] |
| B. | \[\left( \frac{{{\alpha }^{2}}-{{\beta }^{2}}}{\alpha \beta } \right)\,t\] |
| C. | \[\frac{(\alpha +\beta )\,t}{\alpha \beta }\] |
| D. | \[\frac{\alpha \beta \,t}{\alpha +\beta }\] |
| Answer» E. | |
| 8687. |
What is the maximum value of the force F such that the block shown in the arrangement, does not move [IIT-JEE Screening 2003] |
| A. | 20 N |
| B. | 10 N |
| C. | 12 N |
| D. | 15 N |
| Answer» B. 10 N | |
| 8688. |
Three weights W, 2W and 3W are connected to identical springs suspended from a rigid horizontal rod. The assembly of the rod and the weights fall freely. The positions of the weights from the rod are such that [Roorkee 1999] |
| A. | 3W will be farthest |
| B. | W will be farthest |
| C. | All will be at the same distance |
| D. | 2W will be farthest |
| Answer» D. 2W will be farthest | |
| 8689. |
A body of mass M is kept on a rough horizontal surface (friction coefficient \[\mu \]). A person is trying to pull the body by applying a horizontal force but the body is not moving. The force by the surface on the body is F, where [MP PET 1997] |
| A. | \[F=Mg\] |
| B. | \[F=\mu Mgf\] |
| C. | \[Mg\le F\le Mg\sqrt{1+{{\mu }^{2}}}\] |
| D. | \[Mg\ge F\ge Mg\sqrt{1+{{\mu }^{2}}}\] |
| Answer» D. \[Mg\ge F\ge Mg\sqrt{1+{{\mu }^{2}}}\] | |
| 8690. |
The mass of a body measured by a physical balance in a lift at rest is found to be m. If the lift is going up with an acceleration a, its mass will be measured as [MP PET 1994] |
| A. | \[m\left( 1-\frac{a}{g} \right)\] |
| B. | \[m\left( 1+\frac{a}{g} \right)\] |
| C. | m |
| D. | Zero |
| Answer» D. Zero | |
| 8691. |
A particle of mass \[m\] moves on the x-axis as follows : it starts from rest at \[t=0\] from the point \[x=0\] and comes to rest at \[=(u+at)t+\frac{1}{2}a{{t}^{2}}\] at the point \[x=1\]. No other information is available about its motion at intermediate time \[(0 |
| A. | \[\alpha \] cannot remain positive for all \[t\] in the interval \[0\le t\le 1\] |
| B. | \[|\alpha |\] cannot exceed 2 at any point in its path |
| C. | \[|\alpha |\] must be \[\ge 4\] at some point or points in its path |
| D. | \[\alpha \] must change sign during the motion but no other assertion can be made with the information given |
| Answer» B. \[|\alpha |\] cannot exceed 2 at any point in its path | |
| 8692. |
A block of mass 0.1 kg is held against a wall by applying a horizontal force of 5 N on the block. If the coefficient of friction between the block and the wall is 0.5, the magnitude of the frictional force acting on the block is [IIT 1994] |
| A. | 2.5 N |
| B. | 0.98 N |
| C. | 4.9 N |
| D. | 0.49 N |
| Answer» C. 4.9 N | |
| 8693. |
The motion of a body is given by the equation \[\frac{dv(t)}{dt}=6.0-3v(t)\]. where \[v(t)\] is speed in \[m/s\] and \[t\] in \[\sec \]. If body was at rest at \[t=0\] [IIT-JEE 1995] |
| A. | The terminal speed is 2.0 \[m/s\] |
| B. | The speed varies with the time as \[v(t)=2(1-{{e}^{-3t}})m/s\] |
| C. | The speed is \[0.1m/s\] when the acceleration is half the initial value |
| D. | The magnitude of the initial acceleration is \[6.0m/{{s}^{2}}\] |
| Answer» B. The speed varies with the time as \[v(t)=2(1-{{e}^{-3t}})m/s\] | |
| 8694. |
A ship of mass \[3\times {{10}^{7}}\,kg\] initially at rest is pulled by a force of \[5\times {{10}^{4}}\,N\] through a distance of 3 m. Assume that the resistance due to water is negligible, the speed of the ship is [IIT 1980; MP PMT 2000] |
| A. | 1.5 m/s |
| B. | 60 m/s |
| C. | 0.1 m/s |
| D. | 5 m/s |
| Answer» D. 5 m/s | |
| 8695. |
Which of the following is correct, when a person walks on a rough surface [IIT 1981] |
| A. | The frictional force exerted by the surface keeps him moving |
| B. | The force which the man exerts on the floor keeps him moving |
| C. | The reaction of the force which the man exerts on floor keeps him moving |
| D. | None of the above |
| Answer» D. None of the above | |
| 8696. |
A closed compartment containing gas is moving with some acceleration in horizontal direction. Neglect effect of gravity. Then the pressure in the compartment is [IIT-JEE 1999] |
| A. | Same everywhere |
| B. | Lower in front side |
| C. | Lower in rear side |
| D. | Lower in upper side |
| Answer» C. Lower in rear side | |
| 8697. |
The acceleration of a particle is increasing linearly with time \[t\] as \[bt\]. The particle starts from the origin with an initial velocity \[{{v}_{0}}\] The distance travelled by the particle in time \[t\] will be [CBSE PMT 1995] |
| A. | \[{{v}_{0}}t+\frac{1}{3}b{{t}^{2}}\] |
| B. | \[{{v}_{0}}t+\frac{1}{3}b{{t}^{3}}\] |
| C. | \[{{v}_{0}}t+\frac{1}{6}b{{t}^{3}}\] |
| D. | \[{{v}_{0}}t+\frac{1}{2}b{{t}^{2}}\] |
| Answer» D. \[{{v}_{0}}t+\frac{1}{2}b{{t}^{2}}\] | |
| 8698. |
A flat plate moves normally with a speed \[{{v}_{1}}\] towards a horizontal jet of water of uniform area of cross-section. The jet discharges water at the rate of volume V per second at a speed of \[{{v}_{2}}\]. The density of water is \[\rho \]. Assume that water splashes along the surface of the plate at right angles to the original motion. The magnitude of the force acting on the plate due to the jet of water is [IIT 1995] |
| A. | \[\rho V{{v}_{1}}\] |
| B. | \[\rho V({{v}_{1}}+{{v}_{2}})\] |
| C. | \[\frac{\rho V}{{{v}_{1}}+{{v}_{2}}}v_{1}^{2}\] |
| D. | \[\rho \left[ \frac{V}{{{v}_{2}}} \right]{{({{v}_{1}}+{{v}_{2}})}^{2}}\] |
| Answer» E. | |
| 8699. |
One day on a spacecraft corresponds to 2 days on the earth. The speed of the spacecraft relative to the earth is [CBSE PMT 1993] |
| A. | \[1.5\times {{10}^{8}}m{{s}^{-1}}\] |
| B. | \[2.1\times {{10}^{8}}m{{s}^{-1}}\] |
| C. | \[2.6\times {{10}^{8}}m{{s}^{-1}}\] |
| D. | \[5.2\times {{10}^{8}}m{{s}^{-1}}\] |
| Answer» D. \[5.2\times {{10}^{8}}m{{s}^{-1}}\] | |
| 8700. |
A stick of 1 m is moving with velocity of \[2.7\times {{10}^{8}}m{{s}^{-1}}\]. What is the apparent length of the stick \[(c=3\times {{10}^{8}}m{{s}^{-1}})\] [BHU 1995] |
| A. | 10 m |
| B. | 0.22 m |
| C. | 0.44 m |
| D. | 2.4 m |
| Answer» D. 2.4 m | |