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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.
| 11151. |
While measuring the speed of sound by performing a resonance column experiment, a student gets the first resonance condition at a column length of 18 cm during winter. Repeating the same experiment during summer, he measures the column length to be \[x\] centimeter for the second resonance. Then |
| A. | 18 >\[x\] |
| B. | \[x\]>54 |
| C. | 54>\[x\]>36 |
| D. | 36>\[x\]>18 |
| Answer» C. 54>\[x\]>36 | |
| 11152. |
The diagram below shows the propagation of a wave. Which points are in same phase [AIIMS 1982] |
| A. | F, G |
| B. | C and E |
| C. | B and G |
| D. | B and F |
| Answer» E. | |
| 11153. |
Assertion : Like sound, light can not propagate in vacuum. Reason : Sound is a square wave. It propagates in a medium by a virtue of damping oscillation. [AIIMS 2000] |
| 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. |
| Answer» E. | |
| 11154. |
Assertion : Sound travel faster in solids than gases. Reason : Solid possess greater density than gases. [AIIMS 2000] |
| 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. |
| Answer» C. If assertion is true but reason is false. | |
| 11155. |
Assertion : The fundamental frequency of an open organ pipe increases as the temperature is increased. Reason : As the temperature increases, the velocity of sound increases more rapidly than length of the pipe. |
| 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. |
| Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion. | |
| 11156. |
If wavelength of a wave is \[\lambda =6000{AA}.\] Then wave number will be [MH CET 2002] |
| A. | \[166\times {{10}^{3}}\] m?1 |
| B. | \[16.6\times {{10}^{-1}}\] m?1 |
| C. | \[1.66\times {{10}^{6}}\] m?1 |
| D. | \[1.66\times {{10}^{7}}\] m?1 |
| Answer» D. \[1.66\times {{10}^{7}}\] m?1 | |
| 11157. |
The temperature at which the speed of sound in air becomes double of its value at \[{{0}^{o}}C\] is [AIEEE 2002] |
| A. | 273K |
| B. | 546K |
| C. | 1092K |
| D. | 0K |
| Answer» D. 0K | |
| 11158. |
Two speakers connected to the same source of fixed frequency are placed 2.0 m apart in a box. A sensitive microphone placed at a distance of 4.0m from their midpoint along the perpendicular bisector shows maximum response. The box is slowly rotated until the speakers are in line with the microphone. The distance between the midpoint of the speakers and the microphone remains unchanged. Exactly five maximum responses are observed in the microphone in doing this. The wavelength of the sound wave is |
| A. | 0.2 m |
| B. | 0.4 m |
| C. | 0.6 m |
| D. | 0.8 m |
| Answer» C. 0.6 m | |
| 11159. |
An open pipe is in resonance in its 2nd harmonic with tuning fork of frequency\[{{f}_{1}}\]. Now it is closed at one end. If the frequency of the tuning fork is increased slowly from \[{{f}_{1}}\] then again a resonance is obtained with a frequency\[{{f}_{2}}\]. If in this case the pipe vibrates \[{{n}^{th}}\] harmonics then [IIT-JEE (Screening) 2005] |
| A. | \[n=3,\] \[{{f}_{2}}=\frac{3}{4}{{f}_{1}}\] |
| B. | \[n=3,\] \[{{f}_{2}}=\frac{5}{4}{{f}_{1}}\] |
| C. | \[n=5,\] \[{{f}_{2}}=\frac{5}{4}{{f}_{1}}\] |
| D. | \[n=5,\] \[{{f}_{2}}=\frac{3}{4}{{f}_{1}}\] |
| Answer» D. \[n=5,\] \[{{f}_{2}}=\frac{3}{4}{{f}_{1}}\] | |
| 11160. |
Assertion : A tuning fork is made of an alloy of steel, nickel and chromium. Reason : The alloy of steel, nickel and chromium is called elinvar. |
| 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. |
| Answer» C. If assertion is true but reason is false. | |
| 11161. |
Assertion : Solids can support both longitudinal and transverse waves but only longitudinal waves can propagate in gases. Reason : For the propagation of transverse waves, medium must also neccessarly have the property of rigidity. |
| 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. |
| Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion. | |
| 11162. |
A source is moving towards an observer with a speed of 20 m/s and having frequency of 240 Hz. The observer is now moving towards the source with a speed of 20 m/s. Apparent frequency heard by observer, if velocity of sound is 340 m/s, is [CPMT 2000; KCET 2001; MH CET 2004] |
| A. | 240 Hz |
| B. | 270 Hz |
| C. | 280 Hz |
| D. | 360 Hz |
| Answer» C. 280 Hz | |
| 11163. |
A source of sound S is moving with a velocity 50m/s towards a stationary observer. The observer measures the frequency of the source as 1000 Hz. What will be the apparent frequency of the source when it is moving away from the observer after crossing him ? The velocity of sound in the medium is 350 m/s [MP PMT 1994] |
| A. | 750 Hz |
| B. | 857 Hz |
| C. | 1143 Hz |
| D. | 1333 Hz |
| Answer» B. 857 Hz | |
| 11164. |
The Doppler's effect is applicable for [AFMC 1998] |
| A. | Light waves |
| B. | Sound waves |
| C. | Space waves |
| D. | Both (a) and (b) |
| Answer» E. | |
| 11165. |
Consider ten identical sources of sound all giving the same frequency but having phase angles which are random. If the average intensity of each source is \[{{I}_{0}}\], the average of resultant intensity I due to all these ten sources will be [MP PMT 1990] |
| A. | \[I=100\,{{I}_{0}}\] |
| B. | \[I=10\,{{I}_{0}}\] |
| C. | \[I={{I}_{0}}\] |
| D. | \[I=\sqrt{10}\,{{I}_{0}}\] |
| Answer» C. \[I={{I}_{0}}\] | |
| 11166. |
The equation \[y=A{{\cos }^{2}}\left( 2\pi \ nt-2\pi \frac{x}{\lambda } \right)\] represents a wave with [KCET 2002] |
| A. | Amplitude A/2, frequency \[2n\] and wavelength \[\lambda /2\] |
| B. | Amplitude A/2, frequency \[2n\] and wavelength \[\lambda \] |
| C. | Amplitude A, frequency \[2n\] and wavelength \[2\lambda \] |
| D. | Amplitude A, frequency \[n\] and wavelength \[\lambda \] |
| Answer» B. Amplitude A/2, frequency \[2n\] and wavelength \[\lambda \] | |
| 11167. |
It is found that \[|A+B|\,=\,|A|\]. This necessarily implies. |
| A. | \[B=0\] |
| B. | \[\vec{A},\vec{B}\] antiparallel |
| C. | \[\vec{A},\vec{B}\] are perpendicular |
| D. | \[\vec{A}.\vec{B}\le 0\] |
| Answer» C. \[\vec{A},\vec{B}\] are perpendicular | |
| 11168. |
If \[{{\bar{a}}_{1}}\] and \[{{\bar{a}}_{2}}\] are two non-collinear unit vectors and \[|{{\bar{a}}_{1}}+{{\bar{a}}_{2}}|=\sqrt{3},\] then the value of \[({{\bar{a}}_{1}}-{{\bar{a}}_{2}}).(2{{\bar{a}}_{1}}+{{\bar{a}}_{2}})\] is |
| A. | 2 |
| B. | 44230 |
| C. | ½ |
| D. | 1 |
| Answer» D. 1 | |
| 11169. |
Two forces \[{{\vec{F}}_{1}}=10\hat{i}-\hat{j}-15\hat{k}\] and \[{{\vec{F}}_{2}}=10\hat{i}-\hat{j}-15\hat{k}\] act on a single point. The angle between \[{{\vec{F}}_{1}}\] and \[{{\vec{F}}_{2}}\] is nearly |
| A. | \[{{30}^{o}}\] |
| B. | \[{{45}^{o}}\] |
| C. | \[{{60}^{o}}\] |
| D. | \[{{90}^{o}}\] |
| Answer» C. \[{{60}^{o}}\] | |
| 11170. |
If three vectors along coordinate axes represent the adjacent sides of a cube of length b, then the unit vector along its diagonal passing through the origin will be |
| A. | \[\frac{\hat{i}\,+\,\hat{j}\,+\,\hat{k}}{\sqrt{2}}\] |
| B. | \[\frac{\hat{i}\,+\,\hat{j}\,+\,\hat{k}}{\sqrt{3b}}\] |
| C. | \[\hat{i}\,+\,\hat{j}\,+\,\hat{k}\] |
| D. | \[\frac{\hat{i}\,+\,\hat{j}\,+\,\hat{k}}{\sqrt{3}}\] |
| Answer» E. | |
| 11171. |
A vector \[\vec{a}\] is turned without a change in its length through a small angle \[d\theta \]. The value of \[|\Delta \vec{a}|\] and \[\Delta a\] are respectively |
| A. | \[0,\,a\,d\theta \] |
| B. | \[a,\,d\theta ,\,\,0\] |
| C. | 0, 0 |
| D. | None of these |
| Answer» E. | |
| 11172. |
Given that X \[\vec{A}\,+\vec{B}+\vec{C}\]= 0, out of three vectors two are equal in magnitude and the magnitude of third vector is \[\sqrt{2}\] times that of either of two having equal magnitude. Then, angle between vectors are given by |
| A. | \[30{}^\circ ,\text{ }60{}^\circ ,\text{ }90{}^\circ \] |
| B. | \[45{}^\circ ,\text{ }45{}^\circ ,\text{ }90{}^\circ \] |
| C. | \[90{}^\circ ,\text{ }135{}^\circ ,\text{ }45{}^\circ \] |
| D. | \[90{}^\circ ,\text{ }135{}^\circ ,\text{ }135{}^\circ \] |
| Answer» E. | |
| 11173. |
The sum of the magnitudes of two forces acting at point is 18 and the magnitude of their resultant is 12. If the resultant is at \[90{}^\circ \] with the force of smaller magnitude, what are the magnitudes of forces? |
| A. | 12, 5 |
| B. | 14, 4 |
| C. | 5, 13 |
| D. | 10, 8 |
| Answer» D. 10, 8 | |
| 11174. |
If \[\vec{a}\times \vec{b}\,+\vec{c}=0,\] then \[\vec{a}\times \vec{b}\,\] is |
| A. | \[\vec{a}\times \vec{b}\] |
| B. | \[\vec{c}\times \vec{b}\,\] |
| C. | \[\vec{a}\times \vec{c}\] |
| D. | None of these |
| Answer» B. \[\vec{c}\times \vec{b}\,\] | |
| 11175. |
The vectors from origin to the points A and B are \[\vec{A}=3\hat{i}\,-6\hat{j}\,+2\hat{k}\] and \[\vec{B}=2\hat{i}+\,\hat{j}\,-2\hat{k}\] respectively. The area of the triangle OAB be |
| A. | \[\frac{5}{2}\,\sqrt{17}\,sq\,units\] |
| B. | \[\frac{2}{5}\,\sqrt{17}\,sq\,unit\] |
| C. | \[\frac{3}{5}\,\sqrt{17}\,sq\,unit\] |
| D. | \[\frac{5}{3}\,\sqrt{17}\,sq\,unit\] |
| Answer» B. \[\frac{2}{5}\,\sqrt{17}\,sq\,unit\] | |
| 11176. |
P, Q and R are three coplanar forces acting at a point and are in equilibrium. Given \[P=1.9318\,kg\,wt,\] \[sin{{\theta }_{1}}=0.9659,\] the value of R is (in kg wt) |
| A. | 0.9659 |
| B. | 2 |
| C. | 1 |
| D. | \[\frac{1}{2}\] |
| Answer» D. \[\frac{1}{2}\] | |
| 11177. |
What is correct? |
| A. | \[|\vec{a}-\vec{b}|\,=|\vec{a}|-|\vec{b}|\] |
| B. | \[|\vec{a}-\vec{b}|\,\le |\vec{a}|-|\vec{b}|\] |
| C. | \[|\vec{a}-\vec{b}|\,\ge |\vec{a}|-|\vec{b}|\] |
| D. | \[|\vec{a}-\vec{b}|\,<|\vec{a}|-|\vec{b}|\] |
| Answer» E. | |
| 11178. |
The resultant of \[\vec{A}\] and \[\vec{B}\] is \[{{\vec{R}}_{1}}\]. On reversing the vector \[\vec{B},\] the resultant becomes \[{{\vec{R}}_{2}}\]. What is the value of \[R_{1}^{2}\,+\,R_{2}^{2}\,?\] |
| A. | \[{{A}^{2}}+\,{{B}^{2}}\] |
| B. | \[{{A}^{2}}-{{B}^{2}}\] |
| C. | \[2({{A}^{2}}+\,{{B}^{2}})\] |
| D. | \[2({{A}^{2}}-\,{{B}^{2}})\] |
| Answer» D. \[2({{A}^{2}}-\,{{B}^{2}})\] | |
| 11179. |
The unit vector parallel to the resultant of the vectors \[\overrightarrow{A}=4\hat{i}+3j+6\hat{k}\] and \[\overrightarrow{B}=-\hat{i}+3j-8\hat{k}\] is |
| A. | \[\frac{1}{7}(3\hat{i}+6j-2\hat{k})\] |
| B. | \[\frac{1}{7}(3\hat{i}+6j+2\hat{k})\] |
| C. | \[\frac{1}{49}(3\hat{i}+6j-2\hat{k})\] |
| D. | \[\frac{1}{49}(3\hat{i}-6j+2\hat{k})\] |
| Answer» B. \[\frac{1}{7}(3\hat{i}+6j+2\hat{k})\] | |
| 11180. |
The angle between two vector \[\overrightarrow{A}\And \overrightarrow{B}\] is \[\theta \]. vector \[\overrightarrow{R}\] is the resultant of vectors \[\overrightarrow{A}\And \overrightarrow{B},\] if \[\overrightarrow{R}\] makes an angle \[\frac{\theta }{2}\] with \[\overrightarrow{A}\] then |
| A. | A = 2B |
| B. | A = B/2 |
| C. | A = B |
| D. | AB = 1 |
| Answer» D. AB = 1 | |
| 11181. |
A moves with 65 km/h while B is coming back of A with 80 km/h. The relative velocity of B with respect to A is [AFMC 2000] |
| A. | 80 km/h |
| B. | 60 km/h |
| C. | 15 km/h |
| D. | 145 km/h |
| Answer» D. 145 km/h | |
| 11182. |
A person aiming to reach the exactly opposite point on the bank of a stream is swimming with a speed of 0.5 m/s at an angle of \[120{}^\circ \] with the direction of flow of water. The speed of water in the stream is [CBSE PMT 1999] |
| A. | 1 m/s |
| B. | 0.5 m/s |
| C. | 0.25 m/s |
| D. | 0.433 m/s |
| Answer» D. 0.433 m/s | |
| 11183. |
A man can swim with velocity v relative to water. He has to cross a river of width d flowing with a velocity u (u > v). The distance through which he is carried down stream by the river is x. Which of the following statement is correct |
| A. | If he crosses the river in minimum time \[x=\frac{du}{v}\] |
| B. | x can not be less than \[\frac{du}{v}\] |
| C. | For x to be minimum he has to swim in a direction making an angle of \[\frac{\pi }{2}+{{\sin }^{-1}}\left( \frac{v}{u} \right)\] with the direction of the flow of water |
| D. | x will be max. if he swims in a direction making an angle of \[\frac{\pi }{2}+{{\sin }^{-1}}\frac{v}{u}\] with direction of the flow of water |
| Answer» 1 , 3. x can not be less than \[\frac{du}{v}\] | |
| 11184. |
The angle between the vectors \[\overrightarrow{A}\] and \[\overrightarrow{B}\] is \[\theta .\]The value of the triple product \[\overrightarrow{A}\,.\,(\overrightarrow{B}\times \overrightarrow{A}\,)\] is [CBSE PMT 1991, 2005] |
| A. | \[{{A}^{2}}B\] |
| B. | Zero |
| C. | \[{{A}^{2}}B\sin \theta \] |
| D. | \[{{A}^{2}}B\cos \theta \] |
| Answer» C. \[{{A}^{2}}B\sin \theta \] | |
| 11185. |
If \[|\vec{A}\times \vec{B}|=\sqrt{3}\vec{A}.\vec{B},\] then the value of\[|\vec{A}+\vec{B}|\] is [CBSE PMT 2004] |
| A. | \[{{\left( {{A}^{2}}+{{B}^{2}}+\frac{AB}{\sqrt{3}} \right)}^{1/2}}\] |
| B. | \[A+B\] |
| C. | \[{{({{A}^{2}}+{{B}^{2}}+\sqrt{3}AB)}^{1/2}}\] |
| D. | \[{{({{A}^{2}}+{{B}^{2}}+AB)}^{1/2}}\] |
| Answer» E. | |
| 11186. |
Two adjacent sides of a parallelogram are represented by the two vectors \[\hat{i}+2\hat{j}+3\hat{k}\] and \[3\hat{i}-2\hat{j}+\hat{k}\]. What is the area of parallelogram [AMU 1997] |
| A. | 8 |
| B. | \[8\sqrt{3}\] |
| C. | \[3\sqrt{8}\] |
| D. | 192 |
| Answer» B. \[8\sqrt{3}\] | |
| 11187. |
What is the unit vector perpendicular to the following vectors \[2\hat{i}+2\hat{j}-\hat{k}\] and \[6\hat{i}-3\hat{j}+2\hat{k}\] |
| A. | \[\frac{\hat{i}+10\hat{j}-18\hat{k}}{5\sqrt{17}}\] |
| B. | \[\frac{\hat{i}-10\hat{j}+18\hat{k}}{5\sqrt{17}}\] |
| C. | \[\frac{\hat{i}-10\hat{j}-18\hat{k}}{5\sqrt{17}}\] |
| D. | \[\frac{\hat{i}+10\hat{j}+18\hat{k}}{5\sqrt{17}}\] |
| Answer» D. \[\frac{\hat{i}+10\hat{j}+18\hat{k}}{5\sqrt{17}}\] | |
| 11188. |
The area of the parallelogram represented by the vectors \[\overrightarrow{A}=2\hat{i}+3\hat{j}\] and \[\overrightarrow{B}=\hat{i}+4\hat{j}\] is |
| A. | 14 units |
| B. | 7.5 units |
| C. | 10 units |
| D. | 5 units |
| Answer» E. | |
| 11189. |
The angle between the vectors \[(\hat{i}+\hat{j})\] and \[(\hat{j}+\hat{k})\] is [EAMCET 1995] |
| A. | 30° |
| B. | 45° |
| C. | 60° |
| D. | 90° |
| Answer» D. 90° | |
| 11190. |
Consider a vector \[\overrightarrow{F}=4\hat{i}-3\hat{j}.\]Another vector that is perpendicular to \[\overrightarrow{F}\] is |
| A. | \[4\hat{i}+3\hat{j}\] |
| B. | \[6\hat{i}\] |
| C. | \[7\hat{k}\] |
| D. | \[3\hat{i}-4\hat{j}\] |
| Answer» D. \[3\hat{i}-4\hat{j}\] | |
| 11191. |
If a vector \[2\hat{i}+3\hat{j}+8\hat{k}\]is perpendicular to the vector \[4\hat{j}-4\hat{i}+\alpha \hat{k}\]. Then the value of \[\alpha \] is [CBSE PMT 2005] |
| A. | ?1 |
| B. | \[\frac{1}{2}\] |
| C. | \[-\frac{1}{2}\] |
| D. | 1 |
| Answer» D. 1 | |
| 11192. |
The magnitude of a given vector with end points (4, ? 4, 0) and (? 2, ? 2, 0) must be |
| A. | 6 |
| B. | \[5\sqrt{2}\] |
| C. | 4 |
| D. | \[2\sqrt{10}\] |
| Answer» E. | |
| 11193. |
Two forces of 12 N and 8 N act upon a body. The resultant force on the body has maximum value of [Manipal 2003] |
| A. | 4 N |
| B. | 0 N |
| C. | 20 N |
| D. | 8 N |
| Answer» D. 8 N | |
| 11194. |
If a unit vector is represented by \[0.5\hat{i}+0.8\hat{j}+c\hat{k}\], then the value of ?c? is [CBSE PMT 1999; EAMCET 1994] |
| A. | 1 |
| B. | \[\sqrt{0.11}\] |
| C. | \[\sqrt{0.01}\] |
| D. | \[\sqrt{0.39}\] |
| Answer» C. \[\sqrt{0.01}\] | |
| 11195. |
Assertion : A null vector is a vector whose magnitude is zero and direction is arbitrary. Reason : A null vector does not exist. |
| 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. |
| Answer» D. If the assertion and reason both are false. | |
| 11196. |
A proton of mass 1.6 × 10?27 kg goes round in a circular orbit of radius 0.10 m under a centripetal force of 4 × 10?13 N. then the frequency of revolution of the proton is about [Kerala (Med.) 2002] |
| A. | 0.08 × 108 cycles per sec |
| B. | 4 × 108 cycles per sec |
| C. | 8 × 108 cycles per sec |
| D. | 12 × 108 cycles per sec |
| Answer» B. 4 × 108 cycles per sec | |
| 11197. |
The maximum velocity \[\left( inm{{s}^{1}} \right)\] with which a car driver must traverse a flat curve of radius 150 m and coefficient of friction 0.6 to avoid skidding is [AIEEE 2002] |
| A. | 60 |
| B. | 30 |
| C. | 15 |
| D. | 25 |
| Answer» C. 15 | |
| 11198. |
In uniform circular motion, the velocity vector and acceleration vector are [DCE 2000, 01, 03] |
| A. | Perpendicular to each other |
| B. | Same direction |
| C. | Opposite direction |
| D. | Not related to each other |
| Answer» B. Same direction | |
| 11199. |
The maximum speed of a car on a road?turn of radius 30 m, if the coefficient of friction between the tyres and the road is 0.4, will be [CBSE PMT 2000] |
| A. | 10.84 m/sec |
| B. | 9.84 m/sec |
| C. | 8.84 m/sec |
| D. | 6.84 m/sec |
| Answer» B. 9.84 m/sec | |
| 11200. |
An aeroplane is flying with a uniform speed of 100 m/s along a circular path of radius 100 m. the angular speed of the aeroplane will be [KCET 2000] |
| A. | 1 rad/sec |
| B. | 2 rad/sec |
| C. | 3 rad/sec |
| D. | 4 rad/sec |
| Answer» B. 2 rad/sec | |