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This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
a measuring cylinder contain 50ml of water.a solid of mass 16g is lowered into the cylinder.the water level rises to 58ml find density |
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Answer» density=mass/change in VOLUME or SIMPLY volume=16/(58-50)=16/8=2 gm/cm^3 |
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| 2. |
The near point of a hypermetropic eye is 1m .The power of the lens required to correct this defect is ______ (Assume that the near point of the normal eye is 25 cm |
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Answer» -OBJECT distance (u) = -25 cmImage distance (v) = -1 m = -100 cmTo find :-Nature and power of lens required to correct hypermetropia Concept :-The eye defect called hypermetropia and it is corrected by using convex lens.so,the person requires convex lens spectacles We will first calculate the FOCAL LENGTH of convex lens required in this case.Solution :-HENCE the focal length of the convex lens required will be 33.3 cm.Now,Hence,the power of convex lens required is 3.03 dioptres. |
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| 3. |
Cricket ball of mass 150 g moving at speed of 30 m/s is brought to rest by player in 0.03 find force |
| Answer» MASS of the ball (m) =150 g or 0.15 kg initial velocity (u) =30 m/s time (t) = 0.03 sec. final velocity (v) = 0 Initial MOMENTUM = mu = 0.15 kg * 30 m/s = 4.5 kg m/s Final momentum = mv (which is equal to 0, since v is zero) Change in momentum = mv-mu = 0 - 4.5 = -4.5 kg m/s Average force = Change in momentum / time = -4.5 kg ms^-1 /0.03 s = -150 kg m/s^2 = -150 N The negative sign ACTUALLY shows that the force was applied opposite to the direction of the motion of the ball. So, the average force applied by the PLAYER will be 150 N. | |
| 4. |
A charged particle oscillates about its mean equilibrium position with a frequency of 109 Hz. The frequency of electromagnetic waves produced by the oscillator is (a) 106 Hz (b) 107 Hz (c) 108 Hz (d) 109 Hz |
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Answer» The frequency of an ELECTROMAGNETIC WAVE produced by the oscillator is the same as that of a CHARGED particle OSCILLATING about its mean POSITION i.e., 109 Hz. |
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| 5. |
The ultra high frequency band of radio waves in electromagnetic wave is used as in (a) television waves (b) cellular phone communication (c) commercial FM radio (d) both (a) and (c) |
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Answer» hey mate here's ur ANSWEREXPLANATION:IT IS TELEVISION WAVES and commercial FM radio. MEANS optiond both a and cPLZZZ MARK ME AS BRAINLIST☺ |
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| 6. |
If a variable frequency ac source is connected to a capacitor then with decrease in frequency the displacement current will (a) increase (b) decrease (c) remains constant (d) first decrease then increase |
| Answer» HEY mate here's UR answerExplanation:Current through a capacitor is directly proportional to Impendence. hence decrease in frequency f of the a. c source DECREASES the conduction current. so there will be decrease in the displacement current in the circuit. hence A is the correct✔ optionPLZZ MARK ME AS BRAINLIST☺ | |
| 7. |
The oscillating magnetic field in a plane electromagnetic wave is given as By = (8 × 10-6) sin [2 × 1011t+ 300πx] T, wavelength of the em wave is (a) 0.80 cm (b) 1 × 103m (c) 2 × 10-2cm (d) 0.67 cm |
| Answer» HEY MATE here's UR ANSWEREXPLANATION:It I option D 0.67cmPLZZ MARK ME AS BRAINLIST☺ | |
| 8. |
Which of the following has/have zero average value in a plane electromagnetic wave? (a) Both magnetic and electric fields (b) Electric field only (c) Magnetic field only (d) None of these |
| Answer» ELECTRIC FIELDS have AVERAGE ZERO VALUE | |
| 9. |
Waves in decreasing order of their wavelength are (a) X-rays, infrared rays, visible rays, radio waves (b) radio waves, visible rays, infrared rays, X-rays. (c) radio waves, infrared rays, visible rays, X-rays. (d) radio waves, ultraviolet rays, visible rays, X-rays. |
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Answer» ,,,,,,,,,,,,,,,,,,,,,,,, |
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| 10. |
The conduction current is same as displacement current when source is (a) ac only (b) dc only (c) either ac or dc (d) neither dc nor ac |
| Answer» DC EXPLANATION: ,,,,,,,,,,,,,,,,,,,,,,,,, | |
| 11. |
An electromagnetic wave can be produced, when charge is (a) moving with a constant velocity (b) moving in a circular orbit (c) falling in an electric field (d) both (b) and (c) |
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| 12. |
Maxwell in his famous equations of electromagnetism introduced the concept of (a) ac current (b) displacement current (c) impedance (d) reactance |
| Answer» HEY MATE here's UR answerExplanation:It is ac current PLZZZ MARK ME AS BRAINLIST BRAINLIST☺ | |
| 13. |
The electric field associated with an e.m wave in vacuum is given by \vec{E} =40 cos (kz – 6 × 108) \vec{i}, where E, Z and t are in volt/m, metre and seconds respectively. The value of wave vector K is (a) 2 m-1 (b) 0.5 m-1 (c) 6 m-1 (d) 3 m-1 |
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Answer» The electric field ASSOCIATED with an EM wave in vacuum is GIVEN byThe electric field associated with an electromagnetic wave in vacuum is given by ∣E ∣=40 cos(kz−6×108t), where E, z and t are in VOLT per meter, meter and SECOND respectively. |
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| 14. |
Two resistance 2ohm 4ohm are connected in series find effective resistance |
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| 15. |
Write an experiment to determine the internal diameter of test tube by using Vernier Callipers. |
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| 16. |
220 J of heat is dissipated by a heating element when 0.5 A current flows through it for 10 s.Calculate its resistance |
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Answer» n :Given :-Heat produced = 220JCurrent FLOW = 0.5ATime interval = 10sTo FIND :-RESISTANCE of heating element.Formula :-Formula of heat ENERGY produced by electrical instrument in terms of current flow, resistance and time is given byH DENOTES heat energyI denotes current flowR denotes resistancet denotes time intervalCalculation :- |
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| 17. |
The mass of gas emitted from the rear of toy rocket is initially 0.2kgs.if the speed of the gas relative to the rocket is 4kg.what is the initial Accleration of the rocket? |
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Answer» The acceleration of the rocket in .It is given that,The rate of MASS of the gas EMITTED from rear of a rocket is INITIALLY 0.1 kg/sSpeed of the gas relative to the rocket is 50 mMass of the rocket, m = 2 kgMass PER unit time is given by :t = 20 secondsLet a is the acceleration of the rocket. It is given by :Initial speed, u = 0So, the acceleration of the rocket in . Hence, this is the required solution.Learn more,Acceleration |
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| 18. |
You are trying to buy a plane mirror for your bedroom and you want to get one that will allow you to see your entire body at one time. What is the minimum length of the mirror must be so that you can see your entire body? Explain your answer using a ray diagram. |
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Answer» tion:Ray Diagrams for Plane MirrorsWhat Portion of a Mirror is Required?Right Angle MirrorsOther Multiple Mirror SystemsIn the previous part of this lesson, the use of ray diagrams were introduced and illustrated. Ray diagrams can be USED to determine where a person must sight ALONG a mirror in order to see an image of him/herself. As such, ray diagrams can be used to determine what portion of a plane mirror must be used in order to view an image. The diagram below depicts a 6-foot tall man standing in FRONT of a plane mirror. To see the image of his feet, he must sight along a line towards his feet; and to see the image of the top of his HEAD, he must sight along a line towards the top of his head. The ray diagram depicts these lines of sight and the complete path of light from his extremities to the mirror and to the eye. In order to view his image, the man must look as low as point Y (to see his feet) and as high as point X (to see the tip of his head). The man only needs the portion of mirror extending between points X and Y in order to view his entire image. All other portions of the mirror are useless to the task of this man viewing his own image.The diagram depicts some important information about plane mirrors. Using a cm-ruler, measure the height of the man (the VERTICAL arrow) on the computer screen and measure the distance between points X and Y. What do you notice? The man is twice as tall as the distance between points X and Y. In other words, to view an image of yourself in a plane mirror, you will need an amount of mirror equal to one-half of your height. A 6-foot tall man needs 3-feet of mirror (positioned properly) in order to view his entire image. |
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| 19. |
10. The velocity v of a particle at time t is given by :[CPMT 1990]bV = at +b/t+cThe dimensions of a, b, c are respectively(a) LT-², L, T (b) L², T, LT²(c) LT², LT, L (d) L, LT, T² |
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Answer» a)is CORRECTEXPLANATION:Dimensions of V are LT^-1therefore we have to CHOOSE a option for which time when multiplied with 'a' GIVES the dimensions of speed.Similar COMPARISON should be done with 'b'and'c'.HOPE IT HELPS!!!! |
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| 20. |
1M e V of energy is equivalent to |
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Answer» By definition, it is the amount of ENERGY gained (or lost) by the charge of a single electron moving across an electric POTENTIAL difference of one volt. And mega electron volt (MEV) is 106×eV so 1MeV=1. 6×10−13. |
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| 21. |
.: The first diffraction minima due to a single slit diffraction is at 0 = 30° for a light of wavelength 5000 A. The width of the slit is |
| Answer» TION:The first DIFFRACTION minima DUE to a single SLIT diffraction is at 0 = 30° for a LIGHT of wavelength5000 A.It will help you | |
| 22. |
Please help me to solve this question.. |
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Answer» Explanation:CONSTANT SPEED FROM 3 SEC TO 7 SEC = 4 SECONDS.VARIABLE SPEED (1) FROM 0 SE C TO 3 SEC= 3 SEC (2) FROM 7 SEC TO 9 SEC = 2 SEC ---------------- = 5 SEC.HOPE THIS HELPS. |
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| 23. |
What do you mean by absolute refractive index |
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Answer» In optics, the refractive INDEX or index of refraction of a material is a dimensionless number that describes how fast LIGHT travels through the material. It is defined as. where C is the SPEED of light in VACUUM and v is the phase velocity of light in the medium.MARK IT BRAINLIEST... |
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| 24. |
The SI unit of coefficient of static friction is a) Nb) Nmc) N/md) unit less |
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Answer» tless ____ ✨Thus is because it is a CONSTANT which is DIMENSION LESS ❤️ |
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| 25. |
Why on heating a solid at its melting point,heat energy is converted to potential energy? |
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Answer» Heat is the total ENERGY contained within a substance. As a SOLID is heated, its temperature INCREASES as the molecules move faster. During the phase change, when solid melts into liquid, its temperature remains constant as the heat energy is STORED as potential energy |
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| 26. |
Define Inertia.give its classification. |
| Answer» SORRY I don't KNOW this ANSWER very MUCH sorry for this | |
| 28. |
UUIULIUNE b) A man bought a plot of land for 89, 36,800. On that plot heconstructed a house. He spent 4,96,890 on materials and paidto the labourers. Find the total cost of a house.89,900 |
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| 29. |
please send me the picture of Dinesh Publication or Pradeep chapter electricity class 10 physics . if you don't have this book and you have any refence book then you can also send . but don't answer answer if you don't have any book. |
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| 30. |
Why is it that the word 'AMBULANCE' is usually written in its mirror image in an ambulance ? |
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Answer» Ambulance is written BACKWARDS on the front of the vehicles so that drivers ahead can EASILY read the word from their rear VIEW mirrors, ESPECIALLY in case of an EMERGENCY. |
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| 31. |
Why quantum entanglement Occurs? |
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Answer» Quantum entanglement occurswhen TWO particles become inextricably linked, and whateverhappens to ONE immediately affects the other, regardless of how far apart they are. Hence the 'spooky action at a DISTANCE' description. This PARTICULAR photo SHOWS entanglement between two photons - two light particles. |
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| 32. |
The condition under which a microwave over heats up a food item containing water molecules most efficiently is (a) The frequency of the microwaves must match the resonant frequency of the water molecules. (b) The frequency of the microwaves has no relation with natural frequency of the water molecules. (c) Microwaves are heat waves, so always produce heating. (d) Infrared waves produce heating in a microwave oven. |
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Answer» a)EXPLANATION: |
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| 33. |
Which of the following are not electromagnetic waves? (a) Cosmic rays (b) γ-rays (c) β-rays (d) X-rays |
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Answer» a)COSMIC raysExplanation: |
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| 34. |
The correct option, if speeds of gamma rays, X-rays and microwave are Vg, Vx and Vm respectively will be. (a) Vg > Vx > Vm (b) Vg < Vx < Vm (c) Vg > Vx > Vm (d) Vg = Vx = Vm |
| Answer» C is the CORRECT ANSWER. PLEASE FOLLOW me on the correct answer | |
| 35. |
In electromagnetic wave if ue and um are mean electric and magnetic energy densities respectively, then |
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Answer» rgy in an electromagnetic wave is tied up in the electric and MAGNETIC fields. In GENERAL, the energy per unit volume in an electric field is given by:energy density in electric field= 21 ϵ 0 E 2 In a magnetic field, the energy per unit volume is:energy density in magnetic field= 2μ 0 1B 2 An electromagnetic wave has both electric and magnetic fields, so the total energy density associated with an electromagnetic wave is:u= 21 ϵ 0 E 2 + 2μ 0 1B 2 It TURNS out that for an electromagnetic wave, the energy associated with the electric field is equal to the energy associated with the magnetic field, so the energy density can be written in terms of just one or the other:u= 21 ϵ 0 E 2 = 2μ 0 1B 2 This also implies that in an electromagnetic wave, E = cB. |
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| 36. |
The quantity \sqrt{\mu_{0} \varepsilon_{0}} represents (a) speed of sound (b) speed of light in vacuum (c) speed of e.m.w. (d) inverse of speed of light in vacuum |
| Answer» ELECTROMAGNETIC waves are created by the vibration of an electric charge. This vibration creates a wave which has both an electric and a magnetic component. An electromagnetic wave TRANSPORTS its ENERGY through a vacuum at a speed of 3.00 x 108 m/s (a speed value commonly represented by the symbol c). | |
| 37. |
Electromagnetic waves travelling in a medium having relative permeability μr = 1.3 and relative permittivity Er = 2.14. The speed of electromagnetic waves in medium must be (a) 1.8 × 108 ms-1 (b) 1.8 × 104ms1 (c) 1.8 × 106ms1 (d) 1.8 × 10² ms-1 |
| Answer» ELECTROMAGNETIC WAVES TRAVELLING in a medium which has RELATIVE permeability 1.3 and relative PERMITTIVITY 2.14 speed of electromagnetic waves in this ... | |
| 38. |
Which radiations are used in treatment of muscle ache? (a) Infrared (b) Ultraviolet (c) Microwave (d) X-rays |
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Answer» I THINK it is INFRARED RADIATIONS. |
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| 39. |
The structure of solids is investigated by using (a) cosmic rays (b) X-rays (c) γ-rays (d) infrared rays |
| Answer» TION:X RAYS is the CORRECT ANSWER | |
| 40. |
If \vec{E} and \vec{B} represent electric and magnetic field vector of the electromagnetic waves then the direction of propagation of the em wave is that of |
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Answer» As in an EM wave, the vectors E and B are PERPENDICULAR to each other, the direction of the wave PROPAGATION will be perpendicular to the plane containing the electric and MAGNETIC field vectors |
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| 41. |
From Maxwell’s hypothesis, a charging electric field gives rise to (a) an electric field. (b) an induced emf. (c) a magnetic field. (d) a magnetic dipole. |
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Answer» According to Maxwell's hypothesis, changing of electric FIELD gives RISE to Magnetic field.We KNOW that F=qE,, where F is force and E is electric field.We can relate magnetic field and force by F=qvB, where v is velocity and B is the magnetic field.Therefore we can obtain magnetic field by changing electric field.Therefore option C is correct. |
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| 42. |
Which of the following is called heat radiation? (a) X-rays (b) γ-rays (c) Infrared radiation (d) Microwave |
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| 43. |
In electromagnetic waves the phase difference between electric and magnetic field vectors are (a) zero (b) \frac{\pi}{4} (c) \frac{\pi}{2} (d) π |
| Answer» OPTION C is correct.Explanation:PHI /2 | |
| 44. |
Hey gud evening all of u. can u solve this |
| Answer» HI mate. here is your answer. 5 . 55 Explanation:Given :R1 , R2 , R3 , R4 , R5 , R6 = 3R. so, 1 / Rt = 1 / R1 + 1 / R2 + 1 / R3 + 1 / R4 + 1 / R5 + 1 /R6 .1 / Rt = 1 / 3 + 1 / 3 + 1 / 3 + 1 / 3 + 1 / 3 + 1 / 3 1 / Rt = 0.3 + 0.3 + 0.3 + 0.3 + 0.3 + 0.3 .1 / Rt = 0.18 .Rt ( 1 / Rt ) = 0 . 18 * Rt 1 = 0 . 18 Rt Rt = 1 / 0 . 18 Rt = 5 . 55 .HOPE it helps you mate. please THANK and MARK my answer as brainliest. | |
| 45. |
P= 2t^2+t-5 find dp/dt at t=-1 |
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Answer» -3Explanation: |
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| 46. |
Why is - 273°K is known as absolute zero? |
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Answer» the absolute ZERO.Absolute zero is -273.15 °C or 0 K.It is SAID so,because at this temperature all the PROCESSES STOPS (MEANS everything freezes).leave a like |
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| 47. |
Judge the equivalent resistance when the following are connected in parallel (a) 1 ohm and 100 ohm(b) 3 ohm and 12 ohm |
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Answer» ....................................... |
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| 49. |
1 Find thepotential difference across 8ohm resistor . plzzzzzzzz answer this |
| Answer» SORRY BRO 12345678901234567890 | |