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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.
| 11501. |
A particle executes simple harmonic motion (amplitude = A) between \[x=-A\] and \[x=+A\]. The time taken for it to go from 0 to A/2 is \[{{T}_{1}}\] and to go from A/2 to A is \[{{T}_{2}}\]. Then [IIT-JEE (Screening) 2001] |
| A. | \[{{T}_{1}}<{{T}_{2}}\] |
| B. | \[{{T}_{1}}>{{T}_{2}}\] |
| C. | \[{{T}_{1}}={{T}_{2}}\] |
| D. | \[{{T}_{1}}=2{{T}_{2}}\] |
| Answer» B. \[{{T}_{1}}>{{T}_{2}}\] | |
| 11502. |
The amplitude of a particle executing SHM is made three-fourth keeping its time period constant. Its total energy will be [RPMT 2004] |
| A. | \[\frac{E}{2}\] |
| B. | \[\frac{3}{4}E\] |
| C. | \[\frac{9}{16}E\] |
| D. | None of these |
| Answer» D. None of these | |
| 11503. |
A simple pendulum has time period T1. The point of suspension is now moved upward according to equation \[y=k{{t}^{2}}\] where\[k=1\,m/se{{c}^{2}}\]. If new time period is T2 then ratio \[\frac{T_{1}^{2}}{T_{2}^{2}}\] will be [IIT-JEE (Screening) 2005] |
| A. | 2/3 |
| B. | 5/6 |
| C. | 6/5 |
| D. | 3/2 |
| Answer» D. 3/2 | |
| 11504. |
The function \[{{\sin }^{2}}(\omega t)\]represents [AIEEE 2005] |
| A. | A simple harmonic motion with a period \[2\pi /\omega \] |
| B. | A simple harmonic motion with a period \[\pi /\omega \] |
| C. | A periodic but not simple harmonic motion with a period \[2\pi /\omega \] |
| D. | A periodic but not simple harmonic, motion with a period \[\pi /\omega \] |
| Answer» E. | |
| 11505. |
Three simple harmonic motions in the same direction having the same amplitude a and same period are superposed. If each differs in phase from the next by \[{{45}^{o}}\], then [IIT JEE 1999] |
| A. | The resultant amplitude is \[(1+\sqrt{2)}a\] |
| B. | The phase of the resultant motion relative to the first is 90° |
| C. | The energy associated with the resulting motion is \[(3+2\sqrt{2)}\] times the energy associated with any single motion |
| D. | The resulting motion is not simple harmonic |
| Answer» B. The phase of the resultant motion relative to the first is 90° | |
| 11506. |
The equation of S.H.M. is \[y=a\sin (2\pi nt+\alpha )\], then its phase at time t is [DPMT 2001] |
| A. | \[2\pi nt\] |
| B. | \[\alpha \] |
| C. | \[2\pi nt+\alpha \] |
| D. | \[2\pi t\] |
| Answer» D. \[2\pi t\] | |
| 11507. |
In a triode, \[{{g}_{m}}=2\times {{10}^{-3}}oh{{m}^{-1}};\,\mu =42\], resistance load, \[R=50\] kilo ohm. The voltage amplification obtained from this triode will be [MNR 1999] |
| A. | 30.42 |
| B. | 29.57 |
| C. | 28.18 |
| D. | 27.15 |
| Answer» C. 28.18 | |
| 11508. |
The current in a triode at anode potential 100 V and grid potential ? 1.2 V is 7.5 mA. If grid potential is changed to ? 2.2 V, the current becomes 5.5 mA. the value of trans conductance (gm) will be [RPMT 2003] |
| A. | 2 mili mho |
| B. | 3 mili mho |
| C. | 4 mili mho |
| D. | 0.2 mili mho |
| Answer» B. 3 mili mho | |
| 11509. |
The slope of plate characteristic of a vacuum diode is \[2\times {{10}^{-2}}\,mA/V.\] The plate resistance of diode will be [RPMT 1999] |
| A. | 50 W |
| B. | 50 kW |
| C. | 500 kW |
| D. | 500 kW |
| Answer» C. 500 kW | |
| 11510. |
Which of the following does not vary with plate or grid voltages [BHU (Med.) 1999] |
| A. | gm |
| B. | Rp |
| C. | m |
| D. | Each of them varies |
| Answer» E. | |
| 11511. |
Correct relation for triode is [RPMT 2000] |
| A. | \[\mu ={{g}_{m}}\times {{r}_{p}}\] |
| B. | \[\mu =\frac{{{g}_{m}}}{{{r}_{p}}}\] |
| C. | \[\mu =2{{g}_{m}}\times {{r}_{p}}\] |
| D. | None of these |
| Answer» B. \[\mu =\frac{{{g}_{m}}}{{{r}_{p}}}\] | |
| 11512. |
Select the correct statements from the following [IIT-JEE 1984] |
| A. | A diode can be used as a rectifier |
| B. | A triode cannot be used as a rectifier |
| C. | The current in a diode is always proportional to the applied voltage |
| D. | The linear portion of the I?V characteristic of a triode is used for amplification without distortion |
| Answer» E. | |
| 11513. |
A triode has a mutual conductance of \[2\times {{10}^{-3}}mho\] and an amplification factor of 50. The anode is connected through a resistance of \[25\times {{10}^{3}}\] ohms to a 250 volts supply. The voltage gain of this amplifier is [MP PMT 1989] |
| A. | 50 |
| B. | 25 |
| C. | 100 |
| D. | 12.5 |
| Answer» C. 100 | |
| 11514. |
The triode constant is out of the following [RPMT 1989] |
| A. | Plate resistance |
| B. | Amplification factor |
| C. | Mutual conductance |
| D. | All the above |
| Answer» E. | |
| 11515. |
In a triode valve [MP PET 1992] |
| A. | If the grid voltage is zero then plate current will be zero |
| B. | If the temperature of filament is doubled, then the thermionic current will also be doubled |
| C. | If the temperature of filament is doubled, then the thermionic current will nearly be four times |
| D. | At a definite grid voltage the plate current varies with plate voltage according to Ohm?s law |
| Answer» D. At a definite grid voltage the plate current varies with plate voltage according to Ohm?s law | |
| 11516. |
The amplification produced by a triode is due to the action of [AFMC 1994] |
| A. | Filament |
| B. | Cathode |
| C. | Grid |
| D. | Plate |
| Answer» D. Plate | |
| 11517. |
Thermionic emission from a heated filament varies with its temperature T as [CBSE PMT 1990; RPMT 2000; CPMT 2002] |
| A. | \[{{T}^{-1}}\] |
| B. | \[T\] |
| C. | \[{{T}^{2}}\] |
| D. | \[{{T}^{3/2}}\] |
| Answer» D. \[{{T}^{3/2}}\] | |
| 11518. |
The nearest distance between two atoms in case of a bcc lattice is equal to [J & K CET 2004] |
| A. | \[a\frac{\sqrt{2}}{3}\] |
| B. | \[a\frac{\sqrt{3}}{2}\] |
| C. | \[q\sqrt{3}\] |
| D. | \[\frac{a}{\sqrt{2}}\] |
| Answer» C. \[q\sqrt{3}\] | |
| 11519. |
The energy band diagrams for three semiconductor samples of silicon are as shown. We can then assert that [Haryana CEE 1996] |
| A. | Sample X is undoped while samples Y and Z have been doped with a third group and a fifth group impurity respectively |
| B. | Sample X is undoped while both samples Y and Z have been doped with a fifth group impurity |
| C. | Sample X has been doped with equal amounts of third and fifth group impurities while samples Y and Z are undoped |
| D. | Sample X is undoped while samples Y and Z have been doped with a fifth group and a third group impurity respectively |
| Answer» E. | |
| 11520. |
In a P-type semi-conductor, germanium is dopped with [MH CET 2003] |
| A. | Gallium |
| B. | Boron |
| C. | Aluminium |
| D. | All of these |
| Answer» E. | |
| 11521. |
The valence of the impurity atom that is to be added to germanium crystal so as to make it a N-type semiconductor, is [MNR 1993; MP PET 1994; CBSE PMT 1999; AIIMS 2000] |
| A. | 6 |
| B. | 5 |
| C. | 4 |
| D. | 3 |
| Answer» C. 4 | |
| 11522. |
When phosphorus and antimony are mixed in zermaniun, then [CPMT 2003] |
| A. | P-type semiconductor is formed |
| B. | N-type semiconductor is formed |
| C. | Both (a) and (b) |
| D. | None of these |
| Answer» C. Both (a) and (b) | |
| 11523. |
Resistance of semiconductor at \[0{}^\circ K\] is [RPET 1997] |
| A. | Zero |
| B. | Infinite |
| C. | Large |
| D. | Small |
| Answer» C. Large | |
| 11524. |
For germanium crystal, the forbidden energy gap in joules is [MP PET 2000] |
| A. | \[1.12\times {{10}^{-19}}\] |
| B. | \[1.76\times {{10}^{-19}}\] |
| C. | \[1.6\times {{10}^{-19}}\] |
| D. | Zero |
| Answer» B. \[1.76\times {{10}^{-19}}\] | |
| 11525. |
Energy bands in solids are a consequence of [DCE 1999, 2000; AIEEE 2004] |
| A. | Ohm?s Law |
| B. | Pauli?s exclusion principle |
| C. | Bohr?s theory |
| D. | Heisenberg?s uncertainty principle |
| Answer» C. Bohr?s theory | |
| 11526. |
A hole in a P-type semiconductor is [MP PET 1996] |
| A. | An excess electron |
| B. | A missing electron |
| C. | A missing atom |
| D. | A donor level |
| Answer» C. A missing atom | |
| 11527. |
(USS 133) Indium impurity in germanium makes [EAMCET (Engg.) 1995] |
| A. | N-type |
| B. | P-type |
| C. | Insulator |
| D. | Intrinsic |
| Answer» C. Insulator | |
| 11528. |
The forbidden energy band gap in conductors, semiconductors and insulators are \[E{{G}_{1}},\,E{{G}_{2}}\]and \[E{{G}_{3}}\] respectively. The relation among them is [MP PMT 1994; RPMT 1997] |
| A. | \[E{{G}_{1}}=E{{G}_{2}}=E{{G}_{3}}\] |
| B. | \[E{{G}_{1}}<E{{G}_{2}}<E{{G}_{3}}\] |
| C. | \[E{{G}_{1}}>E{{G}_{2}}>E{{G}_{3}}\] |
| D. | \[E{{G}_{1}}<E{{G}_{2}}>E{{G}_{3}}\] |
| Answer» C. \[E{{G}_{1}}>E{{G}_{2}}>E{{G}_{3}}\] | |
| 11529. |
Three semi-conductors are arranged in the increasing order of their energy gap as follows. The correct arrangement is [MP PMT 1993] |
| A. | Tellurium, germanium, silicon |
| B. | Tellurium, silicon, germanium |
| C. | Silicon, germanium, tellurium |
| D. | Silicon, tellurium, germanium |
| Answer» B. Tellurium, silicon, germanium | |
| 11530. |
Let \[{{n}_{P}}\] and \[{{n}_{e}}\] be the number of holes and conduction electrons respectively in a semiconductor. Then [MP PET 1995] |
| A. | \[{{n}_{P}}>{{n}_{e}}\]in an intrinsic semiconductor |
| B. | \[{{n}_{P}}={{n}_{e}}\]in an extrinsic semiconductor |
| C. | \[{{n}_{P}}={{n}_{e}}\]in an intrinsic semiconductor |
| D. | \[{{n}_{e}}>{{n}_{P}}\]in an intrinsic semiconductor |
| Answer» D. \[{{n}_{e}}>{{n}_{P}}\]in an intrinsic semiconductor | |
| 11531. |
The majority charge carriers in P-type semiconductor are [MP PMT 1999; CBSE PMT 1999; MP PET 1991; MP PET/PMT 1998; MH CET 2003] |
| A. | Electrons |
| B. | Protons |
| C. | Holes |
| D. | Neutrons |
| Answer» D. Neutrons | |
| 11532. |
In the diagram, the input is across the terminals A and C and the output is across the terminals B and D, then the output is [CBSE PMT 1994] |
| A. | Zero |
| B. | Same as input |
| C. | Full wave rectifier |
| D. | Half wave rectifier |
| Answer» D. Half wave rectifier | |
| 11533. |
Zener diode is used as [CBSE PMT 1999] |
| A. | Half wave rectifier |
| B. | Full wave rectifier |
| C. | ac voltage stabilizer |
| D. | dc voltage stabilizer |
| Answer» D. dc voltage stabilizer | |
| 11534. |
Consider the following statements A and B and identify the correct choice of the given answers A zener diode is always connected in reverse bias The potential barrier of a PN junction lies between 0.1 to 0.3 V approximately [EAMCET 2000] |
| A. | A and B are correct |
| B. | A and B are wrong |
| C. | A is correct but B is wrong |
| D. | A is wrong but B is correct |
| Answer» D. A is wrong but B is correct | |
| 11535. |
In order to forward bias a PN junction, the negative terminal of battery is connected to [RPMT 2003] |
| A. | P?side |
| B. | Either P?side or N?side |
| C. | N?side |
| D. | None of these |
| Answer» D. None of these | |
| 11536. |
In a PN junction photo cell, the value of photo-electromotive force produced by monochromatic light is proportional to [CBSE PMT 2004] |
| A. | The voltage applied at the PN junction |
| B. | The barrier voltage at the PN junction |
| C. | The intensity of the light falling on the cell |
| D. | The frequency of the light falling on the cell |
| Answer» D. The frequency of the light falling on the cell | |
| 11537. |
If no external voltage is applied across P-N junction, there would be [Orissa JEE 2002] |
| A. | No electric field across the junction |
| B. | An electric field pointing from N-type to P-type side across the junction |
| C. | An electric field pointing from P-type to N-type side across the junction |
| D. | A temporary electric field during formation of P-N junction that would subsequently disappear |
| Answer» C. An electric field pointing from P-type to N-type side across the junction | |
| 11538. |
PN-junction diode works as a insulator, if connected [CPMT 1987] |
| A. | To A.C. |
| B. | In forward bias |
| C. | In reverse bias |
| D. | None of these |
| Answer» D. None of these | |
| 11539. |
In the given figure, which of the diodes are forward biased? [Kerala PET 2002] 1. 2. 3. 4. 5. |
| A. | 1, 2, 3 |
| B. | 2, 4, 5 |
| C. | 1, 3, 4 |
| D. | 2, 3, 4 |
| Answer» C. 1, 3, 4 | |
| 11540. |
Zener breakdown in a semi-conductor diode occurs when [UPSEAT 2002] |
| A. | Forward current exceeds certain value |
| B. | Reverse bias exceeds certain value |
| C. | Forward bias exceeds certain value |
| D. | Potential barrier is reduced to zero |
| Answer» C. Forward bias exceeds certain value | |
| 11541. |
The resistance of a reverse biased P-N junction diode is about [MP PMT 2000] |
| A. | 1 ohm |
| B. | \[{{10}^{2}}\]ohm |
| C. | \[{{10}^{3}}\]ohm |
| D. | \[{{10}^{6}}\]ohm |
| Answer» E. | |
| 11542. |
Which of the following statements is not true [IIT-JEE 1997 Re-Exam] |
| A. | The resistance of intrinsic semiconductors decrease with increase of temperature |
| B. | Doping pure \[Si\]with trivalent impurities give P-type semiconductors |
| C. | The majority carriers in N-type semiconductors are holes |
| D. | A PN-junction can act as a semiconductor diode |
| Answer» D. A PN-junction can act as a semiconductor diode | |
| 11543. |
The approximate ratio of resistances in the forward and reverse bias of the PN-junction diode is [MP PET 2000; MP PMT 1999, 2002, 03; Pb. PMT 2003] |
| A. | \[{{10}^{2}}:1\] |
| B. | \[{{10}^{-2}}:1\] |
| C. | \[1:{{10}^{-4}}\] |
| D. | \[1:{{10}^{4}}\] |
| Answer» E. | |
| 11544. |
The output of an OR gate is connected to both the inputs of a NAND gate. The combination will serve as a: |
| A. | NOT gate |
| B. | NOR gate |
| C. | AND gate |
| D. | OR gate |
| Answer» C. AND gate | |
| 11545. |
The figure shows a logic circuit with two inputs A and B and the output C. The voltage wave forms across A, B and C are as given. The logic gate circuit is: |
| A. | OR gate |
| B. | NOR gate |
| C. | AND gate |
| D. | NAND gate |
| Answer» B. NOR gate | |
| 11546. |
The current gain in transistor in common base mode is\[0.99\]. To change the emitter current by \[5\,mA,\] the necessary change in collector will be |
| A. | \[0.196\,mA\] |
| B. | \[2.45\,mA\] |
| C. | \[4.95\,mA\] |
| D. | \[5.1mA\] |
| Answer» D. \[5.1mA\] | |
| 11547. |
In common emitter amplifier the \[\frac{{{I}_{c}}}{{{I}_{e}}}\] is\[0.98\]. The current gain will be |
| A. | \[4.9\] |
| B. | \[7.8\] |
| C. | \[49\] |
| D. | \[78\] |
| Answer» D. \[78\] | |
| 11548. |
The transfer ratio \[\beta \] of a transistor is 50. The input resistance of the transistor when used in the common emitter configuration is 1 kn. The peak value of the collector A.C. current for an A.C. input voltage of \[0.01\text{ }V\] peak is |
| A. | \[100\,\mu A\] |
| B. | \[0.01\,mA\] |
| C. | \[0.25\,mA\] |
| D. | \[500\,\mu A\] |
| Answer» E. | |
| 11549. |
The ratio of work function and temperature of two emitters are \[1:2,\] then the ratio of current densities obtained by them will be |
| A. | \[4:1\] |
| B. | \[2:1\] |
| C. | \[1:2\] |
| D. | \[1:4\] |
| Answer» E. | |
| 11550. |
In a npn transistor \[{{10}^{10}}\] electrons enter the emitter in\[{{10}^{-6}}s.\] \[4%\] of the electrons are lost in the base. The current transfer ratio will be |
| A. | \[0.98\] |
| B. | \[0.97\] |
| C. | \[0.96\] |
| D. | \[0.94\] |
| Answer» D. \[0.94\] | |