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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.
| 9201. |
The radius of the earth is 6400 km and \[g=10m/{{\sec }^{2}}\]. In order that a body of 5 kg weighs zero at the equator, the angular speed of the earth is [MP PMT 1985] |
| A. | 1/80 radian/sec |
| B. | 1/400 radian/sec |
| C. | 1/800 radian/sec |
| D. | 1/1600 radian/sec |
| Answer» D. 1/1600 radian/sec | |
| 9202. |
?On flowing current in a conducting wire the magnetic field produces around it.? It is a law of [RPET 2003] |
| A. | Lenz |
| B. | Ampere |
| C. | Ohm |
| D. | Maxwell |
| Answer» C. Ohm | |
| 9203. |
An aircraft is moving with a velocity of \[300\,m{{s}^{-1}}.\] If all the forces acting on it are balanced, then [Kerala PMT 2004] |
| A. | It still moves with the same velocity |
| B. | It will be just floating at the same point in space |
| C. | It will fall down instantaneously |
| D. | It will lose its velocity gradually |
| E. | It will explode |
| Answer» B. It will be just floating at the same point in space | |
| 9204. |
A particle of mass \[{{m}_{1}}\] is moving with a velocity \[{{v}_{1}}\]and another particle of mass \[{{m}_{2}}\]is moving with a velocity \[{{v}_{2}}\]. Both of them have the same momentum but their different kinetic energies are \[{{E}_{1}}\]and \[{{E}_{2}}\]respectively. If \[{{m}_{1}}>{{m}_{2}}\] then [CBSE PMT 2004] |
| A. | \[{{E}_{1}}<{{E}_{2}}\] |
| B. | \[\frac{{{E}_{1}}}{{{E}_{2}}}=\frac{{{m}_{1}}}{{{m}_{2}}}\] |
| C. | \[{{E}_{1}}>{{E}_{2}}\] |
| D. | \[{{E}_{1}}={{E}_{2}}\] |
| Answer» B. \[\frac{{{E}_{1}}}{{{E}_{2}}}=\frac{{{m}_{1}}}{{{m}_{2}}}\] | |
| 9205. |
The electric field between the plates of a parallel plate capacitor when connected to a certain battery is \[{{E}_{0}}\]. If the space between the plates of the capacitor is filled by introducing a material of dielectric constant K without disturbing the battery connections, the field between the plates shall be [AMU (Med.) 2002] |
| A. | \[K{{E}_{0}}\] |
| B. | \[{{E}_{0}}\] |
| C. | \[\frac{{{E}_{0}}}{K}\] |
| D. | None of the above |
| Answer» C. \[\frac{{{E}_{0}}}{K}\] | |
| 9206. |
A micro-wave and an ultrasonic sound wave have the same wavelength. Their frequencies are in the ratio (approximately) [Kerala (Engg.) 2002] |
| A. | 106 : 1 |
| B. | 104 : 1 |
| C. | 102 : 1 |
| D. | 10 : 1 |
| Answer» B. 104 : 1 | |
| 9207. |
A generator produces a voltage that is given by \[V=240\sin 120\,t\], where t is in seconds. The frequency and r.m.s. voltage are [MP PET 1993; MP PMT 1990] |
| A. | 60 Hz and 240 V |
| B. | 19 Hz and 120 V |
| C. | 19 Hz and 170 V |
| D. | 754 Hz and 70 V |
| Answer» D. 754 Hz and 70 V | |
| 9208. |
The Lyman series of hydrogen spectrum lies in the region [MNR 1993; MP PMT 1995; UPSEAT 2002] |
| A. | Infrared |
| B. | Visible |
| C. | Ultraviolet |
| D. | Of \[X-\] rays |
| Answer» D. Of \[X-\] rays | |
| 9209. |
Assertion : Two bodies at different temperatures, if brought in thermal contact do not necessary settle to the mean temperature. Reason : The two bodies may have different thermal capacities. |
| 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. |
| E. | If assertion is false but reason is true. |
| Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion. | |
| 9210. |
Core of transformer is made up of [AFMC 2005] |
| A. | Soft iron |
| B. | Steel |
| C. | Iron |
| D. | Alnico |
| Answer» B. Steel | |
| 9211. |
At what altitude in metre will the acceleration due to gravity be 25% of that at the earth's surface (Radius of earth = R metre) [ISM Dhanbad 1994] |
| A. | \[\frac{1}{4}R\] |
| B. | R |
| C. | \[\frac{3}{8}R\] |
| D. | \[\frac{R}{2}\] |
| Answer» C. \[\frac{3}{8}R\] | |
| 9212. |
The speed of a wave in a medium is 760 m/s. If 3600 waves are passing through a point, in the medium in 2 minutes, then its wavelength is [AFMC 1998; CPMT 2001] |
| A. | 13.8 m |
| B. | 25.3 m |
| C. | 41.5 m |
| D. | 57.2 m |
| Answer» C. 41.5 m | |
| 9213. |
Assertion : Pulling a lawn roller is easier than pushing it. Reason : Pushing increases the apparent weight and hence the force of friction. |
| 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. |
| E. | If assertion is false but reason is true. |
| Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion. | |
| 9214. |
A shell having a hole of radius r is dipped in water. It holds the water upto a depth of h then the value of r is [RPMT 2000] |
| A. | \[r=\frac{2T}{hdg}\] |
| B. | \[r=\frac{T}{hdg}\] |
| C. | \[r=\frac{Tg}{hd}\] |
| D. | None of these |
| Answer» B. \[r=\frac{T}{hdg}\] | |
| 9215. |
Ionization potential of hydrogen atom is 13.6 V. Hydrogen atoms in the ground state are excited by monochromatic radiation of photon energy 12.1 eV. The spectral lines emitted by hydrogen atoms according to Bohr's theory will be [CPMT 1990; CBSE PMT 1996; MP PMT 1999; AMU (Med.) 2002] |
| A. | One |
| B. | Two |
| C. | Three |
| D. | Four |
| Answer» D. Four | |
| 9216. |
At what height from the ground will the value of ?g? be the same as that in 10 km deep mine below the surface of earth [RPET 1999] |
| A. | 20 km |
| B. | 10 km |
| C. | 15 km |
| D. | 5 km |
| Answer» B. 10 km | |
| 9217. |
A body weight W newton at the surface of the earth. Its weight at a height equal to half the radius of the earth will be [UPSEAT 2002] |
| A. | \[\frac{W}{2}\] |
| B. | \[\frac{2W}{3}\] |
| C. | \[\frac{4W}{9}\] |
| D. | \[\frac{8W}{27}\] |
| Answer» D. \[\frac{8W}{27}\] | |
| 9218. |
The ratio of secondary to primary turns is \[9:4.\] If power input is P, what will be the ratio of power output (neglect all losses) to power input [DCE 1999] |
| A. | 4 : 9 |
| B. | 9 : 4 |
| C. | 5 : 4 |
| D. | 1 : 1 |
| Answer» E. | |
| 9219. |
Rutherford?s a-particle experiment showed that the atoms have [AFMC 2001] |
| A. | Proton |
| B. | Nucleus |
| C. | Neutron |
| D. | Electrons |
| Answer» C. Neutron | |
| 9220. |
Assertion : In meter bridge experiment, a high resistance is always connected in series with a galvanometer. Reason : As resistance increases current through the circuit increases. |
| 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. |
| E. | If assertion is false but reason is true. |
| Answer» D. If the assertion and reason both are false. | |
| 9221. |
Field inside a solenoid is [MP PMT 1993] |
| A. | Directly proportional to its length |
| B. | Directly proportional to current |
| C. | Inversely proportional to total number of turns |
| D. | Inversely proportional to current |
| Answer» C. Inversely proportional to total number of turns | |
| 9222. |
Assertion : Sudden fall of pressure at a place indicates strom. Reason : Air flows from higher pressure to lower pressure. |
| 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. |
| E. | If assertion is false but reason is true. |
| Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion. | |
| 9223. |
A rocket can go vertically upwards in earth's atmosphere because [CPMT 1980] |
| A. | It is lighter than air |
| B. | Of gravitational pull of the sun |
| C. | It has a fan which displaces more air per unit time than the weight of the rocket |
| D. | Of the force exerted on the rocket by gases ejected by it |
| Answer» E. | |
| 9224. |
A body weighs 700 gm wt on the surface of the earth. How much will it weigh on the surface of a planet whose mass is \[\frac{1}{7}\] and radius is half that of the earth [CMC Vellore 1984; AFMC 2000] |
| A. | 200 gm wt |
| B. | 400 gm wt |
| C. | 50 gm wt |
| D. | 300 gm wt |
| Answer» C. 50 gm wt | |
| 9225. |
Assertion : A man would feel iron or wooden balls equally hot at 98.4°F. Reason : At 98.4°F both iron and wood have same thermal conductivity. |
| 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. |
| E. | If assertion is false but reason is true. |
| Answer» D. If the assertion and reason both are false. | |
| 9226. |
The compressibility of a material is |
| A. | Product of volume and its pressure |
| B. | The change in pressure per unit change in volume strain |
| C. | The fractional change in volume per unit change in pressure |
| D. | None of the above |
| Answer» D. None of the above | |
| 9227. |
The coil of choke in a circuit [AIIMS 2001] |
| A. | Increases the current |
| B. | Decreases the current |
| C. | Does not change the current |
| D. | Has high resistance to dc circuit |
| Answer» C. Does not change the current | |
| 9228. |
Two forces 3N and 2 N are at an angle q such that the resultant is R. The first force is now increased to 6N and the resultant become 2R. The value of q is [HP PMT 2000] |
| A. | \[\text{3}0{}^\circ \] |
| B. | \[\text{6}0{}^\circ \] |
| C. | \[\text{9}0{}^\circ \] |
| D. | \[\text{12}0{}^\circ \] |
| Answer» E. | |
| 9229. |
The first line in the Lyman series has wavelength l. The wavelength of the first line in Balmer series is [MH CET (Med.) 2001] |
| A. | \[\frac{2}{9}\,\lambda \] |
| B. | \[\frac{9}{2}\,\lambda \] |
| C. | \[\frac{5}{27}\,\lambda \] |
| D. | \[\frac{27}{5}\lambda \] |
| Answer» E. | |
| 9230. |
If a body looses half of its velocity on penetrating 3 cm in a wooden block, then how much will it penetrate more before coming to rest [AIEEE 2002; DCE 2002] |
| A. | 1 cm |
| B. | 2 cm |
| C. | 3 cm |
| D. | 4 cm |
| Answer» B. 2 cm | |
| 9231. |
Two bodies of masses 2m and m have their K.E. in the ratio 8 : 1, then their ratio of momenta is [EAMCET (Engg.) 1995] |
| A. | 1 : 1 |
| B. | 2 : 1 |
| C. | 4 : 1 |
| D. | 8 : 1 |
| Answer» D. 8 : 1 | |
| 9232. |
An electron changes its position from orbit \[n=4\] to the orbit \[n=2\] of an atom. The wavelength of the emitted radiation?s is (R = Rydberg?s constant) [BHU 2004] |
| A. | \[\frac{16}{R}\] |
| B. | \[\frac{16}{3R}\] |
| C. | \[\frac{16}{5R}\] |
| D. | \[\frac{16}{7R}\] |
| Answer» C. \[\frac{16}{5R}\] | |
| 9233. |
In which frequency range, space waves are normally propagated [EAMCET 2002] |
| A. | HF |
| B. | VHF |
| C. | UHF |
| D. | SHF |
| Answer» D. SHF | |
| 9234. |
When a tuning fork vibrates, the waves produced in the fork are [AFMC 2001] |
| A. | Longitudinal |
| B. | Transverse |
| C. | Progressive |
| D. | Stationary |
| Answer» B. Transverse | |
| 9235. |
Two vibrating tuning forks produce progressive waves given by \[{{Y}_{1}}=4\sin 500\pi t\]and \[{{Y}_{2}}=2\sin 506\pi t.\] Number of beats produced per minute is [CBSE PMT 2005] |
| A. | 360 |
| B. | 180 |
| C. | 3 |
| D. | 60 |
| Answer» C. 3 | |
| 9236. |
The frequency of tuning forks A and B are respectively 3% more and 2% less than the frequency of tuning fork C. When A and B are simultaneously excited, 5 beats per second are produced. Then the frequency of the tuning fork 'A' (in Hz) is [EAMCET 2001] |
| A. | 98 |
| B. | 100 |
| C. | 103 |
| D. | 105 |
| Answer» D. 105 | |
| 9237. |
The number of waves contained in unit length of the medium is called [AIIMS 1998] |
| A. | Elastic wave |
| B. | Wave number |
| C. | Wave pulse |
| D. | Electromagnetic wave |
| Answer» C. Wave pulse | |
| 9238. |
Assertion : Newton?s second law of motion gives the measurement of force. Reason : According to Newton?s second law of motion, force is directly proportional to the rate of change of momentum. |
| 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. |
| E. | If assertion is false but reason is true. |
| Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion. | |
| 9239. |
An electron is accelerated through a potential difference of 1000 volts. Its velocity is nearly [MP PMT 1985; Pb. PET 2003] |
| A. | \[\frac{{{\nu }_{1}}-{{\nu }_{2}}}{k-1}\] |
| B. | \[1.9\times {{10}^{6}}m/s\] |
| C. | \[1.9\times {{10}^{7}}m/s\] |
| D. | \[2\sqrt{2}V\] |
| Answer» D. \[2\sqrt{2}V\] | |
| 9240. |
In short wave communication waves of which of the following frequencies will be reflected back by the ionospheric layer, having electron density 1011 per m3 [AIIMS 2003] |
| A. | 2 MHz |
| B. | 10 MHz |
| C. | 12 MHz |
| D. | 18 MHz |
| Answer» B. 10 MHz | |
| 9241. |
An inductive circuit contains a resistance of 10 ohm and an inductance of 2.0 henry. If an ac voltage of 120 volt and frequency of 60 Hz is applied to this circuit, the current in the circuit would be nearly [CPMT 1990; MP PET 2002] |
| A. | 0.32 amp |
| B. | 0.16 amp |
| C. | 048 amp |
| D. | 0.80 amp |
| Answer» C. 048 amp | |
| 9242. |
Assertion : The cross product of a vector with itself is a null vector. Reason : The cross-product of two vectors results in a vector quantity. |
| 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. |
| E. | If assertion is false but reason is true. |
| Answer» C. If assertion is true but reason is false. | |
| 9243. |
Which of the following cylindrical rods will conduct most heat, when their ends are maintained at the same steady temperature [CPMT 1981; NCERT 1973, 81; MP PMT 1987; CBSE PMT 1995] |
| A. | Length 1 m; radius 1 cm |
| B. | Length 2 m; radius 1 cm |
| C. | Length 2 m; radius 2 cm |
| D. | Length 1 m; radius 2 cm |
| Answer» E. | |
| 9244. |
Assertion : The electromagnetic waves of shorter wavelength can travel longer distances on earth's surface than those of longer wavelengths. Reason : Shorter the wavelength, the larger is the velocity of wave propagation. |
| 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. |
| E. | If assertion is false but reason is true. |
| Answer» D. If the assertion and reason both are false. | |
| 9245. |
If temperature scale is changed from °C to °F, the numerical value of specific heat will [CPMT 1984] |
| A. | Increases |
| B. | Decreased |
| C. | Remains unchanged |
| D. | None of the above |
| Answer» C. Remains unchanged | |
| 9246. |
The peak value of 220 volts of ac mains is [CPMT 1990; MP PMT 1999; MP PET 2000; RPET2001] |
| A. | 155.6 volts |
| B. | 220.0 volts |
| C. | 311.0 volts |
| D. | 440 volts |
| Answer» D. 440 volts | |
| 9247. |
Identify the wrong statement in the following. Coulomb's law correctly describes the electric force that [KCET 2005] |
| A. | Binds the electrons of an atom to its nucleus |
| B. | Binds the protons and neutrons in the nucleus of an atom |
| C. | Binds atoms together to form molecules |
| D. | Binds atoms and molecules together to form solids |
| Answer» C. Binds atoms together to form molecules | |
| 9248. |
An electric lamp is connected to 220 V, 50 Hz supply. Then the peak value of voltage is [AFMC 1996] |
| A. | 210 V |
| B. | 211 V |
| C. | 311 V |
| D. | 320 V |
| Answer» D. 320 V | |
| 9249. |
Of two masses of 5 kg each falling from height of 10 m, by which 2kg water is stirred. The rise in temperature of water will be [RPET 1997] |
| A. | 2.6°C |
| B. | 1.2°C |
| C. | 0.32°C |
| D. | 0.12°C |
| Answer» E. | |
| 9250. |
One Tesla is equal to [AFMC 1998] |
| A. | \[{{10}^{7}}\,gauss\] |
| B. | \[{{10}^{-4}}\,gauss\] |
| C. | \[{{10}^{4}}\,gauss\] |
| D. | \[{{10}^{-8}}\,gauss\] |
| Answer» D. \[{{10}^{-8}}\,gauss\] | |