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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.
| 5101. |
A stone projected with a velocity \[u\] at an angle \[\theta \] With the horizontal reaches maximum height \[{{H}_{1}}\] When it is projected with velocity u at an angle \[(\frac{\pi }{2}-\theta )\] with the horizontal, it reaches maximum height \[{{H}_{2}}\]. The relation between the horizontal range R of the projectile, \[{{H}_{1}}\]and \[{{H}_{2}}\]is |
| A. | \[R=4\sqrt{{{H}_{1}}{{H}_{2}}}\] |
| B. | \[R=\,4({{H}_{1}}-{{H}_{2}})\] |
| C. | \[R=\,4({{H}_{1}}+{{H}_{2}})\] |
| D. | \[R=\,\frac{{{H}^{2}}_{1}}{{{H}^{2}}_{2}}\] |
| Answer» B. \[R=\,4({{H}_{1}}-{{H}_{2}})\] | |
| 5102. |
A man swimming downstream overcome a float at a point M After travelling distance D he turned back and passed the float at a distance of D/2 from the point M, then the ratio of speed of swimmer with respect to still water to the speed of the river will be |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | 2.5 |
| Answer» C. 4 | |
| 5103. |
A train is moving at a constant speed V when its driver observes another train in front of him on the same track and moving in the same direction with constant speed v. If the distance between the trains is x, then what should be the minimum retardation of the train so as to avoid collision? |
| A. | \[\frac{(V+v)_{{}}^{2}}{x}\] |
| B. | \[\frac{(V-v)_{{}}^{2}}{x}\] |
| C. | \[\frac{(V+v)_{{}}^{2}}{2x}\] |
| D. | \[\frac{(V-v)_{{}}^{2}}{2x}\] |
| Answer» E. | |
| 5104. |
A police party is chasing a dacoit in a jeep which is moving at a constant speed v. The dacoit is on a motorcycle. When he is at a distance x from the jeep, he accelerates from rest at a constant rate. Which of the following relations is true if the police is able to catch the dacoit? |
| A. | \[{{v}^{2}}\le \alpha x\] |
| B. | \[{{v}^{2}}\le 2\alpha x\] |
| C. | \[{{v}^{2}}\ge 2\alpha x\] |
| D. | \[{{v}^{2}}\ge \alpha x\] |
| Answer» D. \[{{v}^{2}}\ge \alpha x\] | |
| 5105. |
A particle moves with uniform acceleration along a straight line AB. Its velocities at A and B are 2 m/s and 14 m/s, respectively. M is the mid-point of AB. The particle takes \[{{t}_{1}}\] seconds to go from A to M and \[{{t}_{2}}\] seconds to go from M to B. Then \[{{t}_{2}}/{{t}_{1}}\] is |
| A. | 1 : 1 |
| B. | 0.0840277777777778 |
| C. | 1:2 |
| D. | 0.125694444444444 |
| Answer» D. 0.125694444444444 | |
| 5106. |
A drunkard is walking along a straight road. He takes five steps forward and three steps backward and so on. Each step is 1 m long and takes 1 s. There is a pit on the road 11 m away from the starting point. The drunkard will fall into the pit after |
| A. | 29 s |
| B. | 21 s |
| C. | 37 s |
| D. | 31 s |
| Answer» B. 21 s | |
| 5107. |
Two trains, which are moving along different tracks in opposite directions, are put on the same track due to a mistake. Their drivers, on noticing the mistake, start slowing down the trains when the trains are 300 m apart. Graphs given below show their velocities as function of time as the trains slow down. The separation between the trains when both have stopped is |
| A. | 120 m |
| B. | 280 m |
| C. | 60 m |
| D. | 20 m |
| Answer» E. | |
| 5108. |
A projectile is fired vertically upwards with an initial velocity \[u\]. After an interval of T seconds, a second projectile is fired vertically upwards, also with initial velocity \[u\]. |
| A. | They meet at time \[t=\frac{u}{g}\] and at a height \[\frac{{{u}^{2}}}{2g}+\frac{g{{T}^{2}}}{8}\] |
| B. | They meet at time\[t=\frac{u}{g}+\frac{T}{2}\] and at a height \[\frac{{{u}^{2}}}{2g}+\frac{g{{T}^{2}}}{8}\] |
| C. | They meet at time \[t=\frac{u}{g}+\frac{T}{2}\] and at a height \[\frac{{{u}^{2}}}{2g}-\frac{g{{T}^{2}}}{8}\] |
| D. | They never meet |
| Answer» D. They never meet | |
| 5109. |
A particle is moving in a straight line and passes through a point \[O\] with a velocity of 6 \[m{{s}^{-1}}\] .The particle moves with a constant retardation of 2 \[m{{s}^{-2}}\] for 4 s and there after moves with constant velocity. How long after leaving \[O\] does the particle return to \[o\]? |
| A. | 3 s |
| B. | 8 s |
| C. | Never |
| D. | 4 s |
| Answer» C. Never | |
| 5110. |
A body starts from rest with uniform acceleration. If its velocity after n second is v, then its displacement in the last two seconds is |
| A. | \[\frac{2v(n+1)}{n}\] |
| B. | \[\frac{v(n+1)}{n}\] |
| C. | \[\frac{v(n-1)}{n}\] |
| D. | \[\frac{2v(n-1)}{n}\] |
| Answer» E. | |
| 5111. |
Three forces start acting simultaneously on a particle moving with velocity \[{{v}^{\to }}\]. These forces are represented in magnitude and direction by the three sides of a triangle ABC (as shown). The particle will now move with velocity |
| A. | \[\overrightarrow{v}\]remaining unchanged |
| B. | less than \[\overrightarrow{v}\] |
| C. | greater than \[\overrightarrow{v}\] |
| D. | \[\left| \overrightarrow{v} \right|\] in the direction of the largest force BC |
| Answer» B. less than \[\overrightarrow{v}\] | |
| 5112. |
An insect moving along a straight line, travels in every second distance equal to the magnitude of time elapsed. Assuming acceleration to be constant, and the insect starts at \[t=0\]. Find the magnitude of initial velocity of insect |
| A. | \[\frac{3}{2}unit\] |
| B. | \[\frac{5}{4}unit\] |
| C. | \[2\,unit\] |
| D. | \[\frac{1}{2}unit\] |
| Answer» E. | |
| 5113. |
A particle moving in a straight line covers half the distance with speed of 3 m/s. The other half of the distance is covered in two equal time intervals with speed of 4.5 m/s and 7.5 m/s respectively. The average speed of the particle during this motion is |
| A. | 4.0 m/s |
| B. | 5.0 m/s |
| C. | 5.5 m/s |
| D. | 4.8 m/s |
| Answer» B. 5.0 m/s | |
| 5114. |
A particle is thrown up inside a stationary lift of sufficient height. The time of flight is T. Now it is thrown again with same initial speed\[{{v}_{0}}\]with respect to lift. At the time of second throw, lift is moving up with speed \[{{v}_{0}}\] and uniform acceleration g upward (the acceleration due to gravity). The new time of flight is |
| A. | \[\sqrt{2T}\] |
| B. | \[\frac{T}{2}\] |
| C. | \[T\] |
| D. | \[2T\] |
| Answer» C. \[T\] | |
| 5115. |
The electric potential between a proton and an electron is given by\[V={{V}_{0}}\,In\,\frac{r}{{{r}_{0}}}\], where \[{{r}_{0}}\]is a constant. Assuming Bohr's model to he-applicable, write variation of \[{{r}_{n}}\] with n, n being the principal quantum number |
| A. | \[{{r}_{n}}\propto n\] |
| B. | \[{{r}_{n}}\propto 1/n\] |
| C. | \[{{r}_{n}}\propto {{n}^{2}}\] |
| D. | \[{{r}_{n}}\propto 1/{{n}^{2}}\] |
| Answer» B. \[{{r}_{n}}\propto 1/n\] | |
| 5116. |
A gas of H-atoms in excited state \[{{n}_{2}}\] absorbs a photon of some energy and jump in higher energy state \[{{n}_{1}}\] then it returns to ground state after emitting six different wavelengths in emission spectrum. The energy of emitted photon is equal, less or greater than the energy of absorbed photon then \[{{n}_{1}}\] and \[{{n}_{2}}\] will be |
| A. | \[{{n}_{1}}=5,\,{{n}_{2}}=3\] |
| B. | \[{{n}_{1}}=5,\,{{n}_{2}}=2\] |
| C. | \[{{n}_{1}}=4,\,{{n}_{2}}=3\] |
| D. | \[{{n}_{1}}=4,\,{{n}_{2}}=2\] |
| Answer» E. | |
| 5117. |
The number of revolutions per second made by an electroi in the first Bohr orbit of hydrogen atom is of the order of 3 |
| A. | \[{{10}^{20}}\] |
| B. | \[{{10}^{19}}\] |
| C. | \[{{10}^{17}}\] |
| D. | \[{{10}^{15}}\] |
| Answer» E. | |
| 5118. |
Hydrogen (H), deuterium (4), singly ionized helium (\[H{{e}^{+}}\] and doubly ionized lithium (Li) all have one electroi around the nucleus. Consider n = 2 to n = 1 transition the wavelengths of emitted radiations are \[{{\lambda }_{1}},\]\[{{\lambda }_{2}},\]\[{{\lambda }_{3}},\] and \[{{\lambda }_{4}}\] respectively. Then approximately |
| A. | \[{{\lambda }_{1}}={{\lambda }_{2}}=4{{\lambda }_{3}}=9{{\lambda }_{4}}\] |
| B. | \[4{{\lambda }_{1}}=2{{\lambda }_{2}}=2{{\lambda }_{3}}={{\lambda }_{4}}\] |
| C. | \[{{\lambda }_{1}}=2{{\lambda }_{2}}=2\sqrt{2}{{\lambda }_{3}}=3\sqrt{2}{{\lambda }_{4}}\] |
| D. | \[{{\lambda }_{1}}={{\lambda }_{2}}=2{{\lambda }_{3}}=3\sqrt{2}{{\lambda }_{4}}\] |
| Answer» B. \[4{{\lambda }_{1}}=2{{\lambda }_{2}}=2{{\lambda }_{3}}={{\lambda }_{4}}\] | |
| 5119. |
In hydrogen atom, electron makes transition from n =4 to n = 1 level. Recoil momentum of the H atom will be |
| A. | \[3.4\times {{10}^{-27}}N\text{-}\sec \] |
| B. | \[6.8\times {{10}^{-27}}N\text{-}\sec \] |
| C. | \[3.4\times {{10}^{-24}}N\text{-}\sec \] |
| D. | \[6.8\times {{10}^{-24}}N\text{-}\sec \] |
| Answer» C. \[3.4\times {{10}^{-24}}N\text{-}\sec \] | |
| 5120. |
Let \[{{v}_{1}}\] be the frequency of series limit of Lyman series, \[{{v}_{2}}\] the frequency of the first line of Lyman series and \[{{v}_{3}}\] the frequency of series limit of Balmer series. Then which of the following is correct? |
| A. | \[{{v}_{1}}-{{v}_{2}}={{v}_{3}}\] |
| B. | \[{{v}_{2}}-{{v}_{1}}={{v}_{3}}\] |
| C. | \[{{v}_{3}}=\frac{1}{2}({{v}_{1}}+{{v}_{2}})\] |
| D. | \[{{v}_{2}}+{{v}_{1}}={{v}_{3}}\] |
| Answer» B. \[{{v}_{2}}-{{v}_{1}}={{v}_{3}}\] | |
| 5121. |
A nucleus of mass number A, originally at rest, emits an a-particle with speed v. The daughter nucleus recoils with a speed |
| A. | \[\frac{4v}{A-4}\] |
| B. | \[\frac{4v}{A+4}\] |
| C. | \[\frac{2v}{A+4}\] |
| D. | \[\frac{2v}{A-4}\] |
| Answer» B. \[\frac{4v}{A+4}\] | |
| 5122. |
The radioactivity of sample is \[{{R}_{1}}\] at a time \[{{T}_{1}}\] and \[{{R}_{2}}\] at a time\[{{T}_{2}}\]. If the half-life of the specimen is T, the number of atoms that have disintegrated in the time (\[{{T}_{2}}-{{T}_{1}}\]) is proportional to |
| A. | \[{{R}_{1}}{{T}_{1}}-{{R}_{2}}{{T}_{2}}\] |
| B. | \[{{R}_{1}}-{{R}_{2}}\] |
| C. | \[\frac{({{R}_{1}}-{{R}_{2}})}{4}\] |
| D. | \[({{R}_{1}}-{{R}_{2}})\] |
| Answer» E. | |
| 5123. |
A star initially has 1040 deuterons. It produces energy via the processes \[_{1}{{H}^{2}}+{}_{1}{{H}^{2}}\to {}_{1}{{H}^{3}}+p\] \[_{1}{{H}^{2}}+{}_{1}{{H}^{3}}\to {}_{2}{{H}^{4}}+n\] The masses of the nuclei are as follows: \[M({{H}^{2}})\] = 2.014 amu; M (p) = 1.007 amu; \[M(n)\] = 1.008 amu; \[M(H{{e}^{4}})\] = 4.001 amu If the average power radiated by the star is \[{{10}^{16}}\]W, the deuteron supply of the star is exhausted in a time of the order of |
| A. | \[{{10}^{6}}\] |
| B. | \[{{10}^{8}}\sec \] |
| C. | \[{{10}^{12}}\sec \] |
| D. | \[{{10}^{16}}\sec \] |
| Answer» D. \[{{10}^{16}}\sec \] | |
| 5124. |
A radioactive substance has a half-life of 60 minutes. After 3 hours, the fraction of atom that have decayed would be |
| A. | 12.5% |
| B. | 0.875 |
| C. | 8.5% |
| D. | 0.251 |
| Answer» C. 8.5% | |
| 5125. |
A sample contains 16g of a radioactive material, the half-life of which is two days. After 32 days, the amount of radioactive material left in the sample is Less than 1 mg |
| A. | Less than 1 mg |
| B. | \[\frac{1}{4}g\] |
| C. | \[\frac{1}{2}g\] |
| D. | \[1g\] |
| Answer» B. \[\frac{1}{4}g\] | |
| 5126. |
The electron emitted in beta radiation originates from |
| A. | Inner orbits of atoms |
| B. | Free electrons existing in nuclei |
| C. | Decay of a neutron in a nucleus |
| D. | Photon escaping from the nucleus |
| Answer» D. Photon escaping from the nucleus | |
| 5127. |
The sun radiates energy in all directions. The average radiations received on the earth surface from the sun is 1 4 kilowatt/\[{{m}^{2}}\]. The average earth- sun distance is \[1.5\times {{10}^{11}}\] meters. The mass lost by the sun per day is (1 day = 86400 seconds) |
| A. | \[4.4\times {{10}^{9}}\,kg\] |
| B. | \[7.6\times {{10}^{14}}\,kg\] |
| C. | \[3.8\times {{10}^{12}}\,kg\] |
| D. | \[3.8\times {{10}^{14}}\,kg\] |
| Answer» E. | |
| 5128. |
Which of the following statement is true regarding Bohr's model of hydrogen atom?(I) Orbiting speed of electrons decreases as it falls to discrete orbits away from the nucleus.(II) Radii of allowed orbits of electrons are proportional to the principal quantum number.(III) Frequency with which electrons orbit 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 shirts to outer orbits. Select the correct answer using the codes given below: |
| A. | I and III |
| B. | II and IV |
| C. | I, II and III |
| D. | II, III and IV |
| Answer» B. II and IV | |
| 5129. |
The binding energy of deuteron \[\begin{matrix} 2 \\ 1 \\ \end{matrix}H\] is 1.112 Me V pen nucleon and an \[\alpha \]-particle \[\begin{matrix} 4 \\ 2 \\ \end{matrix}He\] has a binding energy of 7.047 Me V per nucleon. Then in the fusion reaction \[\begin{matrix} 2 \\ 1 \\ \end{matrix}He+\begin{matrix} 2 \\ 1 \\ \end{matrix}H\to \begin{matrix} 4 \\ 2 \\ \end{matrix}He+Q\], the energy Q released is |
| A. | \[1\,MeV\] |
| B. | \[11.9\,MeV\] |
| C. | \[23.8\,MeV\] |
| D. | \[931\,MeV\] |
| Answer» D. \[931\,MeV\] | |
| 5130. |
Water rises to a height h in a capillary tube of cross- sectional area A. The height to which water will rise in a capillary tube of cross-sectional area 4A will be |
| A. | \[h\] |
| B. | \[h/2\] |
| C. | \[h/4\] |
| D. | \[h4\] |
| Answer» C. \[h/4\] | |
| 5131. |
One end of a long iron chain of linear mass density \[\lambda \] is fixed to a sphere of mass m and specific density 1/3 while the other end is free. The sphere along with the chain is immersed in a deep lake. If specific density of iron is the height h above the bed of the lake at which the sphere will float in equilibrium is (Assume that the part of the chain lying on the bottom of the lake exerts negligible force on the upper part of the chain): |
| A. | \[\frac{16}{7}\frac{m}{\lambda }\] |
| B. | \[\frac{7m}{3\lambda }\] |
| C. | \[\frac{5m}{2\lambda }\] |
| D. | \[\frac{8m}{3\lambda }\] |
| Answer» C. \[\frac{5m}{2\lambda }\] | |
| 5132. |
A soap bubble of radius R is blown. After heating the solution a second bubble of radius 2R is blown. The work required to blow the second bubble in comparison to that required for the first bubble is |
| A. | Double |
| B. | Slightly less than double |
| C. | Slightly less than four times |
| D. | Slightly more than four times |
| Answer» D. Slightly more than four times | |
| 5133. |
A 20-cm long capillary tube is dipped in water. The water rises up to 8 cm. If the entire arrangement is put in a freely falling elevator, the length of the water column in the capillary tube will be |
| A. | 20 cm |
| B. | 4 cm |
| C. | 10 cm |
| D. | 8cm |
| Answer» B. 4 cm | |
| 5134. |
The maximum force, in addition to the weight required to pull a wire of 5.0 cm long from the surface of water at temperature \[20{}^\circ C\]is 728 dynes. The surface tension of water is |
| A. | \[7.28\,N/cm\] |
| B. | \[7.28\,dyne/cm\] |
| C. | \[72.8\,dyne/cm\] |
| D. | \[7.28\times {{10}^{2}}\,dyne/cm\] |
| Answer» D. \[7.28\times {{10}^{2}}\,dyne/cm\] | |
| 5135. |
A large open tank has two holes in the wall. One is a square hole of side L at a depth y from the top and the other is a circular hole of radius R at a depth 4y from the top. When the tank is completely filled with water, the quantities of water flowing out per second from both the hole are the same. Then R is equal to |
| A. | \[2\pi L\] |
| B. | \[\frac{L}{\sqrt{2\pi }}\] |
| C. | \[L\] |
| D. | \[\frac{L}{2\pi }\] |
| Answer» C. \[L\] | |
| 5136. |
A tank has a hole at its bottom. The time needed to empty the tank from level \[{{h}_{1}}\] to \[{{h}_{2}}\] will be proportional to |
| A. | \[{{h}_{1}}-{{h}_{2}}\] |
| B. | \[{{h}_{1}}+{{h}_{2}}\] |
| C. | \[\sqrt{{{h}_{1}}}-\sqrt{{{h}_{2}}}\] |
| D. | \[\sqrt{{{h}_{1}}}+\sqrt{{{h}_{2}}}\] |
| Answer» D. \[\sqrt{{{h}_{1}}}+\sqrt{{{h}_{2}}}\] | |
| 5137. |
The flow of blood in a large artery of a anesthetized dog is diverted through a venturimeter. The wider part of the meter has cross-sectional area equal to that of the artery, i.e.,\[10m{{m}^{2}}\]. The narrower part has an area\[5m{{m}^{2}}\]. The pressure drop in the artery is 22 Pa. Density of the blood is\[1.06\times {{10}^{3}}kg{{m}^{-3}}\]. The speed of the blood in the artery is |
| A. | \[0.12\,m\,{{s}^{-1}}\] |
| B. | \[0.62\,m\,{{s}^{-1}}\] |
| C. | \[0.24\,m\,{{s}^{-1}}\] |
| D. | \[0.42\,m\,{{s}^{-1}}\] |
| Answer» B. \[0.62\,m\,{{s}^{-1}}\] | |
| 5138. |
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. | |
| 5139. |
A hollow cylinder of mass m made heavy at its bottom is floating vertically in water. It is tilted from its vertical position through an angle \[\theta \] and is left. The respecting force acting on it is |
| A. | \[mg\,\cos \theta \] |
| B. | \[\frac{mg\,}{\cos \theta }\] |
| C. | \[mg\left[ \frac{1}{\cos \theta }-1 \right]\] |
| D. | \[mg\left[ \frac{1}{\cos \theta }+1 \right]\] |
| Answer» D. \[mg\left[ \frac{1}{\cos \theta }+1 \right]\] | |
| 5140. |
The thickness of the ice layer on the surface of lake is 20 m. A hole is made in the ice layer. What is the minimum length of the rope required to take a bucket full of water out? (Take density of ice =\[0.9\times {{10}^{3}}kg/{{m}^{3}}\]) |
| A. | 2m |
| B. | 5m |
| C. | 9m |
| D. | 18m |
| Answer» B. 5m | |
| 5141. |
A \[U\]-tube containing a liquid is accelerated horizontally with a constant acceleration a. If the separation between the two vertical limbs is \[l\], then the difference in the heights of the liquid in the two arms is |
| A. | Zero |
| B. | \[l\] |
| C. | \[\frac{la}{g}\] |
| D. | \[\frac{la}{a}\] |
| Answer» D. \[\frac{la}{a}\] | |
| 5142. |
A uniform rod of density p is placed in a wide tank containing a liquid of density \[{{\rho }_{0}}(\rho >\rho )\].The depth of liquid in the tank is half the length of the rod. The rod is in equilibrium, with its lower end resting on the bottom of the tank. In this position the rod makes an angle \[\theta \] with the horizontal |
| A. | \[\sin \theta =\frac{1}{2}\sqrt{{{\rho }_{0}}/\rho }\] |
| B. | \[\sin \theta =\frac{1}{2}.\frac{{{\rho }_{0}}}{\rho }\] |
| C. | \[\sin \theta ={{\sqrt{\rho /\rho }}_{0}}\] |
| D. | \[\sin \theta ={{\rho }_{0}}/\rho \] |
| Answer» B. \[\sin \theta =\frac{1}{2}.\frac{{{\rho }_{0}}}{\rho }\] | |
| 5143. |
A sealed tank containing \[a\] liquid of density p moves with horizontal acceleration a as shown in the figure. The difference in pressur between two points \[A\] and \[B\] will be |
| A. | \[h\rho g\] |
| B. | \[l\rho g\] |
| C. | \[h\rho g-l\rho a\] |
| D. | \[h\rho g+l\rho a\] |
| Answer» E. | |
| 5144. |
An iceberg is floating partially immersed in sea water. The density of sea water is \[1.03gc{{m}^{-3}}\] and that of ice is\[0.92gc{{m}^{-3}}\]. The approximate percentage of total volume of iceberg above the level of sea water is |
| A. | 8 |
| B. | 11 |
| C. | 34 |
| D. | 89 |
| Answer» C. 34 | |
| 5145. |
Two holes are made in the side of the tank such that the jets of water flowing out of them meet at the same point on the ground. If one hole is at a height of 3 cm above the bottom, then the distance of the other hole from the top surface of water is |
| A. | \[\frac{3}{2}cm\] |
| B. | \[\sqrt{6}cm\] |
| C. | \[\sqrt{3}cm\] |
| D. | \[3cm\] |
| Answer» E. | |
| 5146. |
A marble of mass \[x\] and diameter 2r is gently released in a tall cylinder containing honey. If the marble displaces mass y (< \[x\]) of the liquid, then the terminal velocity is proportional to |
| A. | \[x+y\] |
| B. | \[x-y\] |
| C. | \[\frac{x+y}{r}\] |
| D. | \[\frac{x-y}{r}\] |
| Answer» E. | |
| 5147. |
A square plate of 0.1 m side moves parallel to a second plate with a velocity of O. 1 m/s, both plates being immersed in water. If the viscous force is 0.002 N and the coefficient of viscosity is 0.01 poise, distance between the plates in m is |
| A. | 0.1 |
| B. | 0.05 |
| C. | 0.005 |
| D. | 0.0005 |
| Answer» E. | |
| 5148. |
A dip needle lies initially in the magnetic meridian when it shows an angle of dip \[\theta \] at a place. The dip circle is rotated through an angle \[x\] in the horizontal plane and then it shows an angle of dip\[\theta '\]. Then \[\frac{\tan \theta '}{\tan \theta }\]is |
| A. | \[\frac{1}{\cos x}\] |
| B. | \[\frac{1}{\sin x}\] |
| C. | \[\frac{1}{\tan x}\] |
| D. | \[\cos x\] |
| Answer» B. \[\frac{1}{\sin x}\] | |
| 5149. |
Two long conductors, separated by a distance d, carry currents\[{{I}_{1}}\] and \[{{I}_{2}}\] in the same direction. They exert a force F on each other. Now the current in one of them is increased to two times and its direction is reversed. The distance is also increased to 3d. The new value of the force between them is |
| A. | \[-2F\] |
| B. | \[F/3\] |
| C. | \[-2F/3\] |
| D. | \[-F/3\] |
| Answer» D. \[-F/3\] | |
| 5150. |
As shown in the figure, a three-sided frame is pivoted at P and Q and hangs vertically. Its sides are of same length and have a linear density of \[\sqrt{3}\] kg/m. A current of \[10\sqrt{3}\] A is sent through the frame, which is in a uniform magnetic field of 2T directed upwards as shown. Then angle through which the frame will be deflected in equilibrium is \[(Take\,g=10\,m/{{s}^{2}})\] |
| A. | \[{{30}^{0}}\] |
| B. | \[{{45}^{0}}\] |
| C. | \[{{60}^{0}}\] |
| D. | \[{{90}^{0}}\] |
| Answer» C. \[{{60}^{0}}\] | |