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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.
| 11551. |
If the given transistor is used as an amplifier then for input resistance of \[80\,\Omega \] and load resistance of \[16\,k\Omega ,\] the output voltage corresponding to the input voltage of \[12mV\] will be |
| A. | \[37.5\,mV\] |
| B. | \[37500\,V\] |
| C. | \[300\,V\] |
| D. | \[300\,mV\] |
| Answer» D. \[300\,mV\] | |
| 11552. |
A npn transistor in a common emitter mode is used as a simple voltage amplifier with a collector current of \[4mA\]. the terminal of a \[8V\] battery is connected to the collector through a load resistance \[{{R}_{L}}\] and to the base through a resistance \[{{R}_{B}}\]. The collector emitter voltage \[{{V}_{CE}}=4V,\] base-emitter voltage \[{{V}_{BE}}=0.6\] and the base current amplification factor \[{{\beta }_{dc}}=100,\]calculate the value of \[{{R}_{B}}.\] |
| A. | \[{{R}_{B}}=15\,k\Omega \] |
| B. | \[{{R}_{B}}=200\,k\Omega \] |
| C. | \[{{R}_{B}}=1\,k\Omega \] |
| D. | \[{{R}_{B}}=185\,k\Omega \] |
| Answer» E. | |
| 11553. |
In a triode, \[{{g}_{m}}=2\times {{10}^{-3}}oh{{m}^{-1}};\] \[\mu =42;\] resistance of load, \[R=50\] kilo ohm. The voltage amplification obtained from this triode will be |
| A. | \[30.42\] |
| B. | \[29.57\] |
| C. | \[28.18\] |
| D. | \[27.15\] |
| Answer» C. \[28.18\] | |
| 11554. |
Copper, a monovalent, has molar mass \[63.54g/mol\]and density \[8.96\text{ }g/c{{m}^{3}}\]. What is the number density n of conduction electron in copper? |
| A. | \[3.2\times {{10}^{20}}\,{{m}^{-3}}\] |
| B. | \[8.49\times {{10}^{26}}\,{{m}^{-3}}\] |
| C. | \[6.2\times {{10}^{31}}\,{{m}^{-3}}\] |
| D. | None |
| Answer» C. \[6.2\times {{10}^{31}}\,{{m}^{-3}}\] | |
| 11555. |
For LED's to emit light in visible region of electromagnetic light, it should have energy band gap in the range of: |
| A. | \[0.1\,eV\] to \[0.4\,eV\] |
| B. | \[0.5\,eV\] to \[0.8\,eV\] |
| C. | \[0.9\,eV\] to \[1.6\,eV\] |
| D. | \[1.7\,eV\] to \[3.0\,eV\] |
| Answer» E. | |
| 11556. |
An experiment is performed to determine the \[1-V\]characteristics of a Zener diode, which has a protective resistance of \[R=100\,\Omega ,\] and a maximum power of dissipation rating of \[1W\]. The minimum voltage range of the DC source in the circuit is: |
| A. | \[0-5\,V\] |
| B. | \[0-24\,V\] |
| C. | \[0-12\,V\] |
| D. | \[0-8\,V\] |
| Answer» D. \[0-8\,V\] | |
| 11557. |
The ratio of electron and hole currents in a semiconductor is \[7/4\] and the ratio of drift velocities of electrons and holes is \[5/4,\] then ratio of concentrations of electrons and holes will be |
| A. | \[5/7\] |
| B. | \[7/5\] |
| C. | \[25/49\] |
| D. | \[49/25\] |
| Answer» C. \[25/49\] | |
| 11558. |
A \[2-V\] battery is connected across the points A and B as shown in the figure given below. Assuming that the resistance of each diode is zero in forward bias, and infinity in reverse bias, the current supplied by the battery when its positive terminal is connected to A, is |
| A. | \[0.2A\] |
| B. | \[0.4A\] |
| C. | \[0.3A\] |
| D. | \[0.1A\] |
| Answer» B. \[0.4A\] | |
| 11559. |
The I-V characteristic of a P-N junction diode is shown below. The approximate dynamic resistance of the p-n junction when a forward bias of 2 volt is applied is |
| A. | \[1\,\Omega \] |
| B. | \[0.25\,\Omega \] |
| C. | \[0.5\,\Omega \] |
| D. | \[5\,\Omega \] |
| Answer» C. \[0.5\,\Omega \] | |
| 11560. |
The plate characteristic curve of a diode in space charge limited region is as shown in the figure. The slope of curve at point P is 5.0 mA/V. The static plate resistance of diode will be |
| A. | 111.1W |
| B. | 222.2W |
| C. | 333.3W |
| D. | 444.4W |
| Answer» D. 444.4W | |
| 11561. |
When a potential difference is applied across, the current passing through [IIT-JEE 1999] |
| A. | An insulator at \[0K\] is zero |
| B. | A semiconductor at \[0K\] is zero |
| C. | A metal at \[0K\] is finite |
| D. | A P-N diode at \[300K\] is finite, if it is reverse biased |
| Answer» C. A metal at \[0K\] is finite | |
| 11562. |
In the CB mode of a transistor, when the collector voltage is changed by 0.5 volt. The collector current changes by 0.05 mA. The output resistance will be [Pb. PMT 2003] |
| A. | 10 kW |
| B. | 20 kW |
| C. | 5 kW |
| D. | 2.5 kW |
| Answer» B. 20 kW | |
| 11563. |
For a common base configuration of PNP transistor \[\frac{{{l}_{C}}}{{{l}_{E}}}=0.98\] then maximum current gain in common emitter configuration will be [CBSE PMT 2002] |
| A. | 12 |
| B. | 24 |
| C. | 6 |
| D. | 5 |
| Answer» C. 6 | |
| 11564. |
A hollow sphere of mass 2 kg is kept on a rough horizontal surface. A force of 10 N is applied at the centre of the sphere as shown in the figure. Find the minimum value \[\mu \]so that the sphere starts pure rolling. (\[Take\,g=10m/{{s}^{2}}\]) |
| A. | \[\sqrt{3}\times 0.16\] |
| B. | \[\sqrt{3}\times 0.08\] |
| C. | \[\sqrt{3}\times 0.1\] |
| D. | Data insufficient |
| Answer» C. \[\sqrt{3}\times 0.1\] | |
| 11565. |
Three particles, each of mass m gram, are situated at the vertices of an equilateral triangle ABC of side f. cm (as shown in the figure). The moment of inertia of the system about a line AX perpendicular to AB and in the plane of ABC, in gram-cm2 units will be |
| A. | \[\frac{3}{2}m{{\ell }^{2}}\] |
| B. | \[\frac{3}{4}m{{\ell }^{2}}\] |
| C. | \[2m{{\ell }^{2}}\] |
| D. | \[\frac{5}{4}m{{\ell }^{2}}\] |
| Answer» E. | |
| 11566. |
Moment of inertia of a hollow cylinder of mass M and radius r about its own axis is |
| A. | \[\frac{2}{3}M{{r}^{2}}\] |
| B. | \[\frac{2}{5}M{{r}^{2}}\] |
| C. | \[\frac{1}{3}M{{r}^{2}}\] |
| D. | \[M{{r}^{2}}\] |
| Answer» E. | |
| 11567. |
Particles of masses m, 2m, 3m,.............nm grams are placed on the same line at distances \[l,\,2l,\,3l,\,.......nl\]cm from a fixed point. The distance of centre of mass of the particles from the fixed point in centimeters is |
| A. | \[\frac{(2n+1)l}{3}\] |
| B. | \[\frac{1}{n+1}\] |
| C. | \[\frac{n({{n}^{2}}+1)l}{2}\] |
| D. | \[\frac{2l}{n({{n}^{2}}+1)}\] |
| Answer» B. \[\frac{1}{n+1}\] | |
| 11568. |
A particle moving in a circular path has an angular momentum of L. If the frequency of rotation is halved, then its angular momentum becomes |
| A. | \[\frac{L}{2}\] |
| B. | L |
| C. | \[\frac{L}{3}\] |
| D. | \[\frac{L}{4}\] |
| Answer» B. L | |
| 11569. |
A wheel rotates with a constant acceleration of 2.0 radian/sec2. If the wheel starts from rest, the number of revolutions it makes in the first ten seconds will be approximately |
| A. | 8 |
| B. | 16 |
| C. | 24 |
| D. | 32 |
| Answer» C. 24 | |
| 11570. |
Three identical spheres, each of mass 1 kg are kept as shown in figure, touching each other, with their centres on a straight line. If their centres are marked P, Q, R respectively, the distance of centre of mass of the system from P is |
| A. | \[\frac{PQ+PR+QR}{3}\] |
| B. | \[\frac{PQ+PR}{3}\] |
| C. | \[\frac{PQ+QR}{3}\] |
| D. | \[\frac{PR+QR}{3}\] |
| Answer» C. \[\frac{PQ+QR}{3}\] | |
| 11571. |
A uniform thin rod AB of length L has linear mass density\[\mu (x)=a+\frac{bx}{L}\], where x is measured from A. If the CM of the rod lies at a distance of \[\left( \frac{7}{12} \right)\]L from A, then a and b are related as : |
| A. | \[a=2b\] |
| B. | \[2a=b\] |
| C. | \[a=b\] |
| D. | \[3a=2b\] |
| Answer» C. \[a=b\] | |
| 11572. |
A spool is pulled horizontally by two equal and opposite forces as shown in fig. Which of Rough the following statements are correct? |
| A. | The centre of mass moves towards left |
| B. | The centre of mass moves towards right |
| C. | The centre of mass remains stationary |
| D. | The net force about the centre of mass of the spool is zero |
| Answer» C. The centre of mass remains stationary | |
| 11573. |
Four particles of masses a \[{{m}_{1,}}\,{{m}_{2,\,}}{{m}_{3,\,}}and\,{{m}_{4,}}\]placed at the vertices A, B, C and D as respectively of a square shown. The COM of the system will lie at diagonal A C if |
| A. | \[{{m}_{1}}={{m}_{3}}\] |
| B. | \[{{m}_{2}}={{m}_{4}}\] |
| C. | \[{{m}_{1}}={{m}_{2}}\] |
| D. | \[{{m}_{3}}={{m}_{4}}\] |
| Answer» C. \[{{m}_{1}}={{m}_{2}}\] | |
| 11574. |
Three masses are placed on the x-axis: 300 g at origin, 500g at \[x=40\text{ }cm\]and 400g at\[x=70cm\]. The distance of the centre of mass from the origin is |
| A. | 40cm |
| B. | 45cm |
| C. | 50cm |
| D. | 30cm |
| Answer» B. 45cm | |
| 11575. |
A triangular set square of angles \[30{}^\circ ,\text{ }60{}^\circ ,\text{ }90{}^\circ \] and of negligible mass is suspended freely from the right angled comer and weights are hung at the two comers. If the hypotenuse of the set square sets horizontally, then the ratio of the weights \[{{W}_{1}}/{{W}_{2}}\] is |
| A. | \[1:1\] |
| B. | \[1:3\] |
| C. | \[\sqrt{3}:1\] |
| D. | \[1:\sqrt{3}\] |
| Answer» C. \[\sqrt{3}:1\] | |
| 11576. |
Three identical thin rods, each of mass \[m\] and length \[\ell \], are joined to form an equilateral triangular frame. The moment of inertia of the frame about an axis parallel to its one side and passing through the opposite vertex is |
| A. | \[\frac{5}{2}m{{\ell }^{2}}\] |
| B. | \[\frac{5}{4}m{{\ell }^{2}}\] |
| C. | \[\frac{3}{2}m{{\ell }^{2}}\] |
| D. | \[\frac{5}{3}m{{\ell }^{2}}\] |
| Answer» C. \[\frac{3}{2}m{{\ell }^{2}}\] | |
| 11577. |
A child is standing with folded hands at the centre of a platform rotating about its central axis. The kinetic energy of the system is K. The child now stretches his arms so that the moment of inertia of the system doubles. The kinetic energy of the system now is |
| A. | \[2K\] |
| B. | \[\frac{K}{2}\] |
| C. | \[\frac{K}{4}\] |
| D. | \[4K\] |
| Answer» C. \[\frac{K}{4}\] | |
| 11578. |
A bar of mass \['m'\] length \[\ell \] is pure translator motion with its centre velocity \[v\]. It collides with another identical bar which is in rest and sticks to it. Assume that after the collision it becomes one system, then the angular velocity of the system after the collision is |
| A. | \[\frac{1}{5}\frac{v}{\ell }\] |
| B. | \[\frac{2}{5}\frac{v}{\ell }\] |
| C. | \[\frac{3}{5}\frac{v}{\ell }\] |
| D. | \[\frac{v}{\ell }\] |
| Answer» D. \[\frac{v}{\ell }\] | |
| 11579. |
A ball falls vertically onto a floor with momentum \[p\], and then bounces repeatedly. If the coefficient of restitution is \[e\], then the total momentum imparted by the ball on the floor till the ball comes to rest is |
| A. | \[p(1+e)\] |
| B. | \[\frac{p}{1-e}\] |
| C. | \[p\left( 1+\frac{1}{e} \right)\] |
| D. | \[p\left( \frac{1+e}{1-e} \right)\] |
| Answer» E. | |
| 11580. |
A ray of light is incident at an angle i from denser to rare medium. The reflected and the refracted rays are mutually perpendicular. The angle of reflection and the angle of refraction are respectively r and r' , then the critical angle will be [IIT-JEE 1983; MP PET 1995; CBSE PMT 1996; MP PMT 1985, 99; Pb. PET 2002] |
| A. | \[{{\sin }^{-1}}(\sin \,r)\] |
| B. | \[{{\sin }^{-1}}\,(\tan r')\] |
| C. | \[{{\sin }^{-1}}\,(\tan i)\] |
| D. | \[{{\tan }^{-1}}(\sin i)\] |
| Answer» D. \[{{\tan }^{-1}}(\sin i)\] | |
| 11581. |
If the critical angle for total internal reflection from a medium to vacuum is \[30{}^\circ \], the velocity of light in the medium is [CPMT 1972; MH CET 2000; KCET 2000; BCECE 2003; RPMT 2003] |
| A. | \[3\times {{10}^{8}}\] m/s |
| B. | \[1.5\times {{10}^{8}}\] m/s |
| C. | \[6\times {{10}^{8}}\] m/s |
| D. | \[\sqrt{3}\times {{10}^{8}}\]m/s |
| Answer» C. \[6\times {{10}^{8}}\] m/s | |
| 11582. |
In the figure shown, for an angle of incidence \[{{45}^{o}},\] at the top surface, what is the minimum refractive index needed for total internal reflection at vertical face [DCE 2002] |
| A. | \[\frac{\sqrt{2}+1}{2}\] |
| B. | \[\sqrt{\frac{3}{2}}\] |
| C. | \[\sqrt{\frac{1}{2}}\] |
| D. | \[\sqrt{2}+1\] |
| Answer» C. \[\sqrt{\frac{1}{2}}\] | |
| 11583. |
Material A has critical angle \[{{i}_{A}},\] and material B has critical angle \[{{i}_{B}}({{i}_{B}}>{{i}_{A}}).\] Then which of the following is true (i) Light can be totally internally reflected when it passes from B to A (ii) Light can be totally internally reflected when it passes from A to B (iii) Critical angle for total internal reflection is \[{{i}_{B}}-{{i}_{A}}\] (iv) Critical angle between A and B is \[{{\sin }^{-1}}\left( \frac{\sin {{i}_{A}}}{\sin {{i}_{B}}} \right)\] [UPSEAT 2004] |
| A. | (i) and (iii) |
| B. | (i) and (iv) |
| C. | (ii) and (iii) |
| D. | (ii) and (iv) |
| Answer» E. | |
| 11584. |
White light is incident on the interface of glass and air as shown in the figure. If green light is just totally internally reflected then the emerging ray in air contains [IIT-JEE (Screening) 2004] |
| A. | Yellow, orange, red |
| B. | Violet, indigo, blue |
| C. | All colours |
| D. | All colours except green |
| Answer» B. Violet, indigo, blue | |
| 11585. |
Critical angle of light passing from glass to air is minimum for [NCERT 1975; RPMT 1999; MP PMT 2002] |
| A. | Red |
| B. | Green |
| C. | Yellow |
| D. | Violet |
| Answer» E. | |
| 11586. |
A diver in a swimming pool wants to signal his distress to a person lying on the edge of the pool by flashing his water proof flash light [NCERT 1972] |
| A. | He must direct the beam vertically upwards |
| B. | He has to direct the beam horizontally |
| C. | He has to direct the beam at an angle to the vertical which is slightly less than the critical angle of incidence for total internal reflection |
| D. | He has to direct the beam at an angle to the vertical which is slightly more than the critical angle of incidence for the total internal reflection |
| Answer» D. He has to direct the beam at an angle to the vertical which is slightly more than the critical angle of incidence for the total internal reflection | |
| 11587. |
Finger prints on a piece of paper may be detected by sprinkling fluorescent powder on the paper and then looking it into [MP PET/PMT 1988] |
| A. | Mercury light |
| B. | Sunlight |
| C. | Infrared light |
| D. | Ultraviolet light |
| Answer» E. | |
| 11588. |
Brilliance of diamond is due to [AIIMS 2002; MP PMT 2003] |
| A. | Shape |
| B. | Cutting |
| C. | Reflection |
| D. | Total internal reflection |
| Answer» E. | |
| 11589. |
Optical fibres are related with [AFMC 2002] |
| A. | Communication |
| B. | Light |
| C. | Computer |
| D. | None of these |
| Answer» B. Light | |
| 11590. |
The refractive index of water is 1.33. The direction in which a man under water should look to see the setting sun is [MP PET 1991; Kerala PET 2002; Pb. PET 2003] |
| A. | \[{{49}^{o}}\]to the horizontal |
| B. | \[{{90}^{o}}\] with the vertical |
| C. | \[{{49}^{o}}\]to the vertical |
| D. | Along the horizontal |
| Answer» D. Along the horizontal | |
| 11591. |
A ray of light propagates from glass (refractive index = 3/2) to water (refractive index = 4/3). The value of the critical angle [JIPMER 1999; UPSEAT 2001; MP PMT 2000, 03] |
| A. | sin?1(1/2) |
| B. | \[{{\sin }^{-1}}\left( \frac{\sqrt{8}}{9} \right)\] |
| C. | \[{{\sin }^{-1}}(8/9)\] |
| D. | \[{{\sin }^{-1}}(5/7)\] |
| Answer» D. \[{{\sin }^{-1}}(5/7)\] | |
| 11592. |
The velocity of light in a medium is half its velocity in air. If ray of light emerges from such a medium into air, the angle of incidence, at which it will be totally internally reflected, is [Roorkee 1999] |
| A. | \[{{15}^{o}}\] |
| B. | \[{{30}^{o}}\] |
| C. | \[{{45}^{o}}\] |
| D. | \[{{60}^{o}}\] |
| Answer» C. \[{{45}^{o}}\] | |
| 11593. |
Total internal reflection is possible when light rays travel [RPMT 1999] |
| A. | Air to water |
| B. | Air to glass |
| C. | Glass to water |
| D. | Water to glass |
| Answer» D. Water to glass | |
| 11594. |
With respect to air critical angle in a medium for light of red colour \[[{{\lambda }_{1}}]\] is q. Other facts remaining same, critical angle for light of yellow colour \[[{{\lambda }_{2}}\]] will be [MP PET 1999] |
| A. | \[\theta \] |
| B. | More than \[\theta \] |
| C. | Less than \[\theta \] |
| D. | \[\frac{\theta {{\lambda }_{1}}}{{{\lambda }_{2}}}\] |
| Answer» D. \[\frac{\theta {{\lambda }_{1}}}{{{\lambda }_{2}}}\] | |
| 11595. |
The reason for shining of air bubble in water is [MP PET 1997; KCET 1999] |
| A. | Diffraction of light |
| B. | Dispersion of light |
| C. | Scattering of light |
| D. | Total internal reflection of light |
| Answer» E. | |
| 11596. |
The critical angle for diamond (refractive index = 2) is [MP PET 2003] |
| A. | \[20{}^\circ \] |
| B. | \[60{}^\circ \] |
| C. | \[45{}^\circ \] |
| D. | \[30{}^\circ \] |
| Answer» E. | |
| 11597. |
Total internal reflection of a ray of light is possible when the (\[{{i}_{c}}\]= critical angle, \[i=\]angle of incidence) [NCERT 1977; MP PMT 1994] |
| A. | Ray goes from denser medium to rarer medium and \[i<{{i}_{c}}\] |
| B. | Ray goes from denser medium to rarer medium and \[i>{{i}_{c}}\] |
| C. | Ray goes from rarer medium to denser medium and \[i>{{i}_{c}}\] |
| D. | Ray goes from rarer medium to denser medium and \[i<{{i}_{c}}\] |
| Answer» C. Ray goes from rarer medium to denser medium and \[i>{{i}_{c}}\] | |
| 11598. |
Total internal reflection of light is possible when light enters from [CPMT 1973; MP PMT 1994] |
| A. | Air to glass |
| B. | Vacuum to air |
| C. | Air to water |
| D. | Water to air |
| Answer» E. | |
| 11599. |
For total internal reflection to take place, the angle of incidence i and the refractive index \[\mu \] of the medium must satisfy the inequality [MP PET 1994] |
| A. | \[\frac{1}{\sin i}<\mu \] |
| B. | \[\frac{1}{\sin i}>\mu \] |
| C. | \[\sin i<\mu \] |
| D. | \[\sin i>\mu \] |
| Answer» B. \[\frac{1}{\sin i}>\mu \] | |
| 11600. |
A light wave travels from glass to water. The refractive index for glass and water are \[\frac{3}{2}\] and \[\frac{4}{3}\] respectively. The value of the critical angle will be: |
| A. | \[{{\sin }^{-1}}\left( \frac{1}{2} \right)\] |
| B. | \[{{\sin }^{-1}}\left( \frac{9}{8} \right)\] |
| C. | \[{{\sin }^{-1}}\left( \frac{8}{9} \right)\] |
| D. | \[{{\sin }^{-1}}\left( \frac{5}{7} \right)\] |
| Answer» D. \[{{\sin }^{-1}}\left( \frac{5}{7} \right)\] | |