This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 16051. |
Observer A is at rest. Source `S_(1)` is moving towards observer A and source `S_(2)` is moving away from observer A. velocity of sound is `330(m)/(sec)`. `beta`= beat frequency heard per second by A. Approximate value of `beta` is: |
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Answer» Correct Answer - 2 `beta=33((330)/(330-10)-(330)/(330+10))` `=33(330(2xx10))/((330)^(2)-(10)^(2))` if `(330)^(2)-(10)^(2)=(330)^(2)` then `beta=33xx(20)/(330)=2Hz` |
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| 16052. |
A parallel-plate capacitor containing a dielectric slab is connected to a cell. The slab is then taken out of the capacitor slowly. Disregard the forces of gravity and friction. For this process, which of the following statements is incorrect? (a) The external agent pulling the slab out will have to perform some work. (b) The potential energy of the capacitor will decrease.(c) The cell will receive some energy. (d) The work done on or by the external agent will be equal to the energy supplied or absorbed by the cell. |
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Answer» Correct Answer is: (d) |
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| 16053. |
A converging lens of focal length f is placed just above a water surface, parallel to the surface, without touching it. A point source, S, of light is placed inside the water, vertically below the lens, at a depth f from it. This arrangement will produce (a) a parallel beam of light emerging from the lens (b) a real image of S in air (c) a virtual image of S in water (d) a virtual image of S in air |
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Answer» Correct Answer is: (c) a virtual image of S in water As seen from the lens, S is at a distance less than f from the lens. |
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| 16054. |
Observer A is at rest. Source `S_(1)` is moving towards observer A and source `S_(2)` is moving away from observer A. velocity of sound is `330(m)/(sec)`. `beta`= beat frequency heard per second by A. Approximate value of `beta` is: |
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Answer» Correct Answer - 2 `beta=33(330/(330-10)-330/(330+10))` `=33(330(2xx10))/((330)^(2)-(10)^(2))` then `beta=33xx20/300=2Hz` |
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| 16055. |
A car is initially at rest, 330 m away from a stationary observer. It begins to move towards the observer with an acceleration of 1.1 m s-2 , sounding its horn continuously. 20 s later, the driver stops sounding the horn. The velocity of sound in air is 330 m s-1 . The observer will hear the sound of the horn for a duration of(a) 20 s (b) 21 s (c) 20 2/3 s (d) 19 1/3 s |
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Answer» Correct Answer is: (a) 20 s Let the car begin to move and sound its horn at time t0. The sound reaches the observer in 1 s. ∴ the observer begins to hear the sound at time t1 = t0 + 1 s. The displacement of the car in 20 s is (1/2) (1.1 m s-2) (20 s)2 = 220 m. ∴ at time t2 = t0 + 20 s, the horn is switched off and the car is 110 m away from the observer. The sound emitted by the horn at the instant it is switched off will travel to the observer in a further time (1/3) s. ∴ the observer stops hearing the sound at time t3 = t2 + 1/3 s. ∴ the observer hears sound for a duration of t = t3 - t1 = t2 + 1/3 s - t1 = (t0 + 20 s) + 1/3 s - (t0 + 1 s) = 19 1/3 s. |
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| 16056. |
Two small balls having equal poistive charges Q( coulomb) on each are suspended by two insulating strings of equal length L(metre) from a hook fixed to a stand. The whole set up is taken in a satellite into space where there is no gravity (state of weightlessness). The angle between the two strings is...............and the tenison in each string is...................newtons. |
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Answer» Where there is no gravitational force, then in this case only electrostatic force of repulsion is acting which will take the two balls as far as possible. The angle between the two strings will be `180^(@)`. The tension in the string will be equal to the electrostatic force of repulsion, i.e., `T=(1)/(4piepsilon_(0))xx(QxxQ)/((2L)^(2))=(1)/(4piepsilon_(0))xx(Q)/(4L^(2))` |
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| 16057. |
Two positively charged particles ` X` and `Y` are initially far away from each other and at rest , `X` begins to move towards `Y` with some initial velocity. The total momentum and energy of the system are `p` and `E`. |
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Answer» Correct Answer - B IF Y is fixed i.e. another force is exist on Y additional to the mutual interaction between X & Y. So the net force on system (X & Y) is not zero p is charged but total always remain conserved. |
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| 16058. |
Find the (a) maximum frequency and (b) minimum wavelength of X-rays produced by 30 kv electrons. |
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Answer» Given V = 30 kV = 30 × 103 volt Energy, E = eV = 1.6 × 10–19 × 30 × 103 = 4.8 × 10–15 joule (a) Maximum Frequency vmax is given by, E = hvmax vmax = E/h = (4.8 x 10-15/6.63 x 10-34 ) = 7.24 x 1018 Hz (b) Minimum wavelength,λmin = c/Vmax = 3x 108/7.28 x1018 = 4.1 × 10–11 m = 0.041 nm |
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| 16059. |
The work function of caesium metal is 2.14 eV. When light of frequency 6 × 1014 Hz is incident on the metal surface, photoemission of electrons occurs. What is the (a) maximum kinetic energy of the emitted electrons ? (b) stopping potential and (c) maximum speed of emitted electrons ? |
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Answer» Given (ϕ0 = 2.14 eV, v = 6 × 1014 Hz (a) Maximum kinetic energy of emitted electron Ek = hv – (ϕ0 = 6.63 × 10–34 × 6 × 1014 –2.14 × 1.6 × 10–19 = 0.54 × 10–19 J =(0.54 x 10-19/1.6 x 10-19 eV) = 0.34 eV (b) Stopping potential v0 is given by Ek = eV0 ⇒V0 = Ek/e = 0.34eV/e = 0.34V (c) Maximum speed (vmax ) of emitted electrons is given by 1/2 mv2max = Ek or vmax = √2Ek/m = √(2 x 0.54 x 10-19/9.1 x 10-31) = 3.44 x 105 m/s |
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| 16060. |
The energy flux of sunlight reaching the surface of earth is 1.388 × 103 W/m2 . How many photons (nearly) per square metre are incident on the earth per second ? Assume that the photons in the sunlight have an average wavelength of 550 nm. |
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Answer» Energy of each photon E = hc/λ = (6.63 x 10-34 x 3 x 108/550 x 10-9) = 3.62 x 10-19 J Number of photons incident on earth’s surface per second per square metre = (Total energy per square metre per second/ Energy of one photon) = (9.388 x 103/3.62 x 10-19 ) = 3.8 x 1021. |
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| 16061. |
A non-conducting ring of radius `0.5 m` carries a total charge of `1.11xx10^(-10)`C distributed non-uniformly on its circumference producing an electric field E everywhere is space. The value of the integral `int_(l=oo)^(l=0)-E.dI (l=0` being centre of the ring) in volt isA. `+2`B. `-1`C. `-2D. `Zero` |
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Answer» Correct Answer - a From definition of potential differecne `overset(1=0)underset(1=oo)intE.d1=potential` difference at infinity and at centre of ring `=(V_(centre)=V_(infinity))` But by convention `V_(infinity)=0 and V_(centre)=(1)/(4piepsilon_(0))(q)/(R )` `=9xx10^(9)xx(1.11xx10^(-10))/(0.5)=2 volt` `therefore overset(1=0)underset(1=oo)(E.di)=2 volt-0 volt =2 volt` |
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| 16062. |
A radioactive sample has a half life of `40` seconds. When its activity is measured `80` seconds after the beginning, it is found to be `6.932xx10^(18)` dps. During this time total energy released is `6xx10^(8)` joule `(ln2=0.6932)`:-A. The initial number of atoms in the simple is `1.6xx10^(20)`B. The initial number of atoms in the sample is `1.6xx10^(21)`C. Energy released per fission is `5xx10^(-13) J`D. Energy released per fission is `(5)/(3)xx10^(-13)J` |
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Answer» Correct Answer - B::C `A = A_(0) e^(-lambda t)` `6.932xx10^(18) = A_(0)e^(-(ln2)/(40)(80))` `= A_(0)e^(-ln4) = (A_(0))/(4)` `A_(0) = 4xx6.932xx10^(18)` `lambda N_(0)= 4xx6.932xx10^(18)` `(0.6932)/(40)N_(0) = 4xx6.932xx10^(18)` `N_(0)=160xx10^(19)` `N_(0) =1.6xx10^(21)` Also `(3)/(4) (1.6xx10^(21))E_(0)=6xx10^(8)` `E_(0)=5xx10^(-13)` |
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| 16063. |
An uncharged capacitor is connected in series with a resistor and a battery. The charging of the capacitor starts at t=0. The rate at which energy stored in the capacitor:-A. first increases then decreasesB. first decreases constantC. continuously decreasesD. |
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Answer» Correct Answer - A Rate of change of energy =V.I. Initially `V_(c)=0` hence `V_(c)I_(e)=0` finally `I_(c)=0` hence `V_(c)I_(c)=0` `therefore` There will be a maxima of power between these two instants. |
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| 16064. |
Two coils of self inductance 100 mH and 400 mH are placed very closed to each other. Find maximum mutual inductance between the two when 4 A current passes through them.A. 200mHB. 300mHC. `100sqrt(2)mH`D. none of these |
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Answer» Correct Answer - A Maximum mutual inductance: `M=sqrt(L_(1)L_(2))=200mH`. |
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| 16065. |
On getting a gift of chappals, the beggar vanished in a minute. Why was he in such a hurry to leave? |
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Answer» When the beggar was asked to leave, he raised his eyes and looked fearfully at the road, which was gleaming in the afternoon heat. He knew his feet would burn again. However, when the children got him a pair of slippers, the beggar stared at it in amazement. He hurriedly flung his towel over his shoulder. Then, he pushed his feet into them and left, muttering a blessing to the children. In a minute, he had vanished around the corner of the street. He was tired and his feet were worn out. Since he could not have got anything better and Rukku Manni wanted him out of the house, he left in a hurry |
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| 16066. |
“A sharp Vshaped line had formed between her eyebrows.” What does it suggest to you about Rukku Manni’s mood? |
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Answer» A sharp Vshaped line between the eyebrows refers to a frown. This suggests that Rukku Manni was in an angry mood. |
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| 16067. |
Just as the violinist began to play, one of the ________ on his violin broke. A) cords B) tapes C) strings D) wires E) chords |
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Answer» Correct option is C) strings |
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| 16068. |
An an ideal parallel `LC` circuit, the capacitor is charged by connecting it to a `DC` source which is then disconnected. The current in the circuitA. becomes zero instantaneouslyB. grow monotonically decays monotonicallyC. decays monotonically.D. oscillates instantaneously. |
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Answer» Correct Answer - C The current in the circuit decays monotonically |
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| 16069. |
She lost her job yesterday. _____ . A) We are proud of her B) I can’t stand her C) I believe in her D) I feel sorry for her |
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Answer» Correct option is D) I feel sorry for her |
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| 16070. |
____you decide to take violin classes let me know. A) While B) Should C) Do D) Because |
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Answer» Correct option is B) Should |
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| 16071. |
He drove so _____ that he lost his job. A) badly B) quick C) cowardly D) worse |
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Answer» Correct option is A) badly |
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| 16072. |
Take an umbrella ____ you won’t get wet. A) so that B) in case C) so D) so after |
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Answer» Correct option is A) so that |
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| 16073. |
A: Why don’ t you send your resume if you want the job? B: I ______ send it, but it got lost in the mail. A) did B) do C) can D) will |
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Answer» Correct option is A) did |
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| 16074. |
Not only did Oscar lose his job, but he ____ his car. A) also damaged B) and an accident C) lost also D) and |
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Answer» Correct option is A) also damaged |
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| 16075. |
____you lost your job, what would you do then? A) When B) After C) So D) Supposing |
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Answer» Correct option is D) Supposing |
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| 16076. |
Write the force balance equation of ideal mass element. |
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Answer» F = M\(\frac{d^2x}{dt^2}\) |
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| 16077. |
Write the force balance equation of ideal dashpot element. |
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Answer» Force balance equation of ideal dashpot element. F = B\(\frac{dx}{dt}\) |
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| 16078. |
Electrooculography (EOG/E.O.G.) is a technique for measuring what?(a) abnormal function of the retina(b) heart rate(c) respiration rate(d) cornea-retinal standing potential |
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Answer» Right choice is (d) cornea-retinal standing potential For explanation: Electrooculography (EOG / E.O.G) is a technique for measuring the potential of the corneal retinal standing potential that exists between the front and back of the human eye. The resulting signal is called electrooculogram. The main applications are in the diagnosis of ophthalmology and the recording of eye movements. |
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| 16079. |
If a person has grievance against the non-issuance of a Job Card, then to whom s/he has to represent the matter? |
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Answer» The matter can be brought to the notice of PO. If the grievance is against the PO, then the matter can be brought to the notice of DPC or the designated grievance-redressal authority at the block or district level. |
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| 16080. |
Should the cost towards Job Card (including the photograph affixed on it) be borne by the applicant? |
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Answer» No, the cost of the Job Cards, including that of the photographs affixed on it, are covered under the administrative expenses and borne as a part of the programme cost. |
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| 16081. |
Who is the custodian of Job Card? |
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Answer» It must be ensured that the JC is always in the custody of the household to whom it is issued. If for any reason i.e., updation of record, it is taken by implementing agencies it should be returned on the same day after the updates. JCs found in the possession of any Panchayat or MGNREGA functionary, without a valid reason, will be considered as an offence punishable under Section 25 of the Act. |
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| 16082. |
Is there any provision to provide duplicate Job Card for a lost one? |
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Answer» Yes, a Job Cardholder may apply for a duplicate Job Card, if the original is lost or damaged. The application will be given to the GP and shall be processed in the manner of a new application, with the difference being that the particulars may also be verified using the duplicate copy of the JC maintained by the Panchayat. |
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| 16083. |
Is there any time-limit to address the grievances in regard to non-issuance of Job Card? |
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Answer» Yes, all such complaints shall be disposed off within 15 days. |
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| 16084. |
This technique involves measuring the optical transmittance of the ear at how many wavelengths?(a) 12(b) 6(c) 8(d) 10 |
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Answer» Correct answer is (c) 8 To explain I would say: In brief, the technique involves measuring the optical transmittance of the ear at 8 wavelengths in the 650 to 1050 nm range. A 2.5 m long flexible fibre ear probe connects the patient to the instrument. |
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| 16085. |
What is a signal flow graph? |
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Answer» A signal flow graph is a diagram that represents a set of simultaneous algebraic equations .By taking L.T the time domain differential equations governing a control system can be transferred to a set of algebraic equations in s‐domain. |
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| 16086. |
Can a job card be cancelled? |
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Answer» No, as per Para 4, Schedule II no job card can be cancelled except where it is found to be a duplicate, or if the entire household has permanently migrated to a place outside the Gram Panchayat and no longer lives in the village. |
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| 16087. |
Feedback characteristics of Control Systems and Effect of feedback on sensitivity. |
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Answer» Feedback characteristics of Control Systems: In control system ,the feedback reduces the error, also reduces the sensitivity of the system to parameter variations .The parameter may vary due to some change in conditions .The variation in parameter affects the performance of the system. So it is necessary to make the system in sensitive to such parameter variations. Effect of feedback on sensitivity : The parameters of any control system changes with the change environment conditions. Also these parameters cannot be constant throughout the life. These parameter variations affect the performance of the system. For example, the resistance of winding of a motor changes due to change in temperature during its operation. • Sensitivity to model uncertainties STG = Ratio of % change in sys T.F./Ratio of % change in process T.F. \(\frac{ΔT}{\frac{T}{\frac{ΔG}{G}}}\) = \(\frac{θ\,in\,T}{θ\,in\,G}=\frac{θ\,T\,G}{θ\,G\,T}\) Open loop: Δγ(s) = ΔG(s)R(s) ΔT(s) = \(\frac{Δγ(s)}{R(s)}\) = ΔG(s) Closed‐loop: T(s) = \(\frac{G}{1+GH}\) ,\(\frac{θT}{θG}=\frac{(1+GH)-GH}{(1+GH)^2}\) = \(\frac{1}{(1+GH)^2}\) STG = \(\frac{θTG}{θGT}\) = \(\frac{1}{(1+GH)^2}\) \(\frac{G}{\frac{G}{1+GH}}\) = \(\frac{1}{(1+GH)}\) → Reduced SK below that of the open‐loop sys by increasing G*H (>>1.0). SHT = \(\frac{θTH}{θHT}\) = \(\frac{-GH}{1+GH}\) * if GH >>1.0 →SK = -1 Feedback components should not be varied with environmental changes →change in H(s) directly affects output response |
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| 16088. |
Commonly used frequency response analysis Methods |
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Answer» Commonly used frequency response analysis Methods are: • Bode plot • Nyquist plot • Nichols chart |
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| 16089. |
What is transmittance? |
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Answer» The transmittance is the gain acquired by the signal when it travels from one node to another node in signal flow graph. |
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| 16090. |
Is there any duration limit fixed for seeking work by adult individuals registered in the JC? |
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Answer» Yes, as per Para 11, Schedule II normally, applications for work must be for at least fourteen days of continuous work, other than the works relating to access to sanitation facilities, for which application for work shall be for atleast six days of continuous work. As per Para 10, Schedule II there shall be no limit on the number of days of employment for which a person may apply, or on the number of days of employment actually provided subject to the aggregate entitlement of the household. |
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| 16091. |
What is the time limit for issuing Job Cards (JC) if the application made is correct? |
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Answer» Within a fortnight after due verification is completed on finding out eligibility of a household, the job cards should be issued to all such eligible households. |
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| 16092. |
Advantages of Bode Plot |
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Answer» Advantages of Bode Plot: • Multiplication of Magnitudes can be converted into addition • A simple method of sketching Bode Plot is based on asymptotic approximations. Such information on straight line asymptotes is sufficient if only rough information on frequency‐ response characteristics is needed. • Should the exact curve be desired, corrections can be made easily to these basic asymptotic plots. • Low frequency response contains sufficient information about the physical characteristics of most of the practical systems. • Experimental determination of a transfer function is possible through Bode plot analysis. |
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| 16093. |
What is Signal flow graph in Control Systems? |
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Answer» A signal flow graph is a diagram that represents a set of simultaneous linear algebraic equations. By taking Laplace transfer, the time domain differential equations governing a control system can be transferred to a set of algebraic equation in s‐domain. A signal‐flow graph consists of a network in which nodes are connected by directed branches. It depicts the flow of signals from one point of a system to another and gives the relationships among the signals. |
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| 16094. |
What is sink and source? |
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Answer» Source is the input node in the signal flow graph and it has only outgoing branches. Sink is an output node in the signal flow graph and it has only incoming branches. |
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| 16095. |
Basic Elements of a Signal flow graph |
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Answer» Basic Elements of a Signal flow graph •Node ‐ a point representing a signal or variable. • Branch – unidirectional line segment joining two nodes. • Path – a branch or a continuous sequence of branches that can be traversed from one node to another node. • Loop – a closed path that originates and terminates on the same node and along the path no node is met twice. • Nonteaching loops – two loops are said to be non touching if they do not have a common node. |
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| 16096. |
Define non touching loop |
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Answer» The loops are said to be non touching if they do not have common nodes. |
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| 16097. |
Figure shows the field lines on a positive charge. Is the work done by the field in moving a small positive charge from Q to P positive or negative? Give reason. |
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Answer» The work done by the field is negative. This is because the charge is moved against the force exerted by the field. |
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| 16098. |
Mason’s gain formula |
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Answer» Mason’s gain formula : The relationship between an input variable and an output variable of signal flow graph is given by the net gain between the input and the output nodes is known as overall gain of the system. Mason‘s gain rule for the determination of the overall system gain is given below. M = \(\frac{1}{Δ}\displaystyle\sum_{K=1}^{N} \)PkΔk = \(\frac{X_{out}}{X_{in}}\) Where M = gain between Xin and Xout Xout = output node variable Xin = input node variable N = total number of forward paths PK = = path gain of the kth forward path Δ = 1‐(sum of loop gains of all individual loop) + (sum of gain product of all possible combinations of two non touching loops) – (sum of gain products of all possible combination of three non touching loops) |
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| 16099. |
Write Masons Gain formula. |
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Answer» Masons Gain formula states that the overall gain of the system is M = \(\frac{1}{Δ}\) \(\displaystyle\sum_{n=1}^{N}\)PhΔh = \(\frac{X_{out}}{x_{in}}\) Where M = gain between Xin and Xout Xout = output node variable Xin = input node variable N = total number of forward paths Pk = path gain of the k the forward path Δ = 1‐(sum of loop gains of all individual loop) + (sum of gain product of all possible combinations of two non touching loops) – (sum of gain products of all possible combination of three non touching loops) |
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| 16100. |
Write the analogous electrical elements in force current analogy for the elements of mechanical translational system. |
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