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InterviewSolution
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.
| 1. |
The dimensional formula of wave number isA. `[M^(o)L^(o)T^(-1)]`B. `[M^(-1)L^(-1)T^(o)]`C. `[M^(o)L^(-1)T^(o)]`D. `[M^(o)L^(o) T^(o)]` |
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Answer» Correct Answer - C Wave number = K = `(1)/(lamda)= [M^(0)L^(-1)T^(0)]` |
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| 2. |
The method of dimensional analysis can be used to derive which of the following relations ?A. `N_0e^(-lamdat)`B. `A sin (omegat+ kx)`C. `(1)/(2)mv^(2) + (1)/(2) I omega^(2)`D. None of the above |
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Answer» Correct Answer - D |
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| 3. |
Which of the following does not have the dimensior of force ?A. Potential gradientB. Energy gradientC. WeightD. Rate of change of momentum |
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Answer» Correct Answer - A Force `= [M^(1)L^(1)T^(-2)]` Weight = mg = `[M][L^(1)T^(-2)] = [M^(1)L^(1)T^(-2)]` Enery gradient `= ([M^(1)L^(2) T^(-2)])/([L^(1)]) = [M^(1)L^(1)T^(-2)]` ltBrgt Potential gradient = `-(dv)/(dx)` `" "= ([M^(1)L^(2)T^(-3)A^(-1)])/([L^(1)]) = [M^(1)L^(1) T^(-3)A^(-1)]` |
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| 4. |
The SI unit of entropy isA. joule/kelvinB. newton-meterC. calorie/secondD. joule/calorie |
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Answer» Correct Answer - A The S.I. unit of entropy is joule/kelvin. |
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| 5. |
If E, M, L and G denote energy, mass, angular momentum and gravitational constant repectively then the quantity `(E^(2)L^(2)//M^(5)G%(2))` has the dimensions of :-A. angleB. lengthC. massD. None of these |
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Answer» Correct Answer - D E `= [ML^(2)T^(-2)]` `M =[M], L= [ML^(2)T^(-1)]`, G `= [M^(-1)L^(3)T^(-2)]` `[(E^(2)L^(2))/(M^(5)G^(2))] = ([ML^(2)T^(-2)]^(2) [ML^(2) T^(-1)]^(2))/([M]&(5)[M^(-1)L^(3)T^(-2)]^(2))` `" "= ([M^(2)L^(4)T^(-4)][M^(2)L^(4)T^(-2)])/([M^(5)][M^(-2) L^(6) T^(-4)]) = ([M^(4)L^(8) T^(-6)])/([M^(3)L^(6)T^(-4)]) = [ML^(2)T^(-2)] ` The quantity `((E^(2)L^(2))/(M^(5)G^(2)))` has the dimensions of energy. None of the given options is correct. |
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| 6. |
Temperature can be expressed as a derived quantity in terms of anyof the followingA. Length and massB. Mass and timeC. Length, mass and timeD. None of these |
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Answer» Correct Answer - D |
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| 7. |
The dinesity of meterial in CGS system of mass is `4g cm^(3)` in a system of unit in which unit of length is `10 cm` and unit of mass is `100g` the value of density of meterial will beA. `0.04`B. `0.4`C. `40`D. `400` |
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Answer» Correct Answer - C Density of material = `4(g)/(cm^(3)) = ( 4 xx 1000)/(100) (100g)/((10 cm)^(3)) = 40 ((100g))/((10 cm)^(3))` |
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| 8. |
One centimetre on the main scale of vernier callipers is divided into ten equal parts. If 20 divisions of vernier scale coincide with 19 small divisions of the main scale then what will be the least count of the callipers. |
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Answer» Correct Answer - 0.005 cm L.C. = `((b-a)/(b)) M.S.D = ((20-19)/(20)) xx (1)/(10)` cm = 0.005 cm |
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| 9. |
In a vernier callipers, N divisions of vernier scale coincide with (N-1) divisions of main scale (in which 1 division represents 1 mm). The least count of the instrument in cm should beA. `N`B. `N-1`C. `(1)/(10N)`D. `(1)/(N-1)` |
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Answer» Correct Answer - C L.C (least count) = 1MSD -1VSD NVSD = (N-1) MSD 1VSD = `((N-1) )/(N)` MSD LC = 1 MSD - `((N-1))/(N)` MSD = `((1)/(N))` MSD = `(1)/(N)` mm LC = `(1)/(10 N )` cm |
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| 10. |
Measure of two quantites along with the precision of respective measuring instrument is `A = 2.5 ms^(-1) +- 0.5 ms^(-1)` `B = 0.10 s +- 0.01s` The value of AB will beA. `(0.25 pm 0.08)` mB. `(0.25 pm 0.5)` mC. `(0.25 pm 0.05)` mD. `(0.25 pm 0.135)`m |
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Answer» Correct Answer - A Let `y =AB` `(Delta y)/(y) = (Delta A)/(A) + (Delta B)/(B)` `y = 2.5 xx 0.1 = 0.25 ` `(Delta y)/( 0.25) = (0.5)/(2.5) + (0.01)/(0.10)` `rArr Deltay = 0. 0 75 = 0.08 (2 SF)` |
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| 11. |
If x, y, z are in arithmetic progression and a is the arithmetic mean of x and y and b is the arithmetic mean of y and z, then prove that y is the arithmetic mean of a and b.A. `x=y lt z`B. `x= y gt z`C. `x lt z lt y`D. `x gt z lt y` |
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Answer» Correct Answer - C `x=a+b = 14 pm 0.14 rArr % `error `= (0.14)/(14) xx 100 = 1% , y = a-b= 2 pm 0.14 rArr % ` error `= (0.14)/(2) xx 100 = 7% ` `z= ab = 48 pm 0.96 rArr %` error `= (0.96)/(48) xx 100 = 2% `. Therefore order of % error is `x lt z lt y` |
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| 12. |
Ab object covers `(16.0 pm 0.4)` m distance in `(4.0 pm 0.2)` s. Find out the speed. |
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Answer» Correct Answer - `(4.0 pm 0.3) m//s` `V = (16.0)/(4.0) = 4.0 m//s` `because (Delta V)/(V) = (Delta s)/(s) + (Delta t)/(t)` `because Delta V = (4.0)[(4.0)/(16.0) + (0.2)/(4.0)] = 4.0 [ 0.2 + 0.5]` `=0.28` after( rounding off) 0.3` `rArr ` Speed `(4.0 pm 0.3) m//s` |
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| 13. |
The external and internal diameters of a hollow cylinder are measured to be `(4.23 pm 0.01)cm ` and `(3.89pm0.01) cm`. The thickness of the wall of the cylinder isA. `(0.34 pm 0.02)` cmB. `(0.17 pm 0.02)` cmC. `(0.17 pm 0.01)` cmD. `(0.34 pm 0.01)` cm |
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Answer» Correct Answer - A Thickness of cylinder can be written as `t = t pm Delta t` `t= r_2 - r_1 = 4.23 - 3.89 = 0.34` `Delta t = Delta r_1 + Delta r_2 = 0.01 + 0.01 = 0.02` ` t (0.34 pm 0.02)` cm |
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| 14. |
Science, like any knowledge, can be put to good or bad use, depending on the user. Given below are some of the applications of science. Formulate your views on whether the particular application is good, bad or something that cannot be so clearly categorized : Mass vaccination against small pox to curb and finally eradicate this disease from the population. (This has already been successfully done in India). (b) Television for eradication of illiteracy and for mass communication of news and ideas. (c ) Prenatal sex determination (d) Computers for increase in work efficiency (e) Putting artificial satellites into orbits around the Earth (f) Development of nuclear weapons (g) Development of new and powerful techniques of chemical and biological warfare). (h) Purification of water for drinking (i) Plastic surgery (f) Cloning |
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Answer» (a) Good, because it helped in eradicating a dreaded disease from the Earth. (b) Good, because it helps in literacy campaign and is an effective method of mass communication and entertainment. Bad, because it leads to practice of abortion in case of female foetus. (d) Good, because it increases work efficiency. (e) Good, because it helped in worldwide communication process. (f) Bad, because nuclear weapons may cause mass destruction of mankind. (g) Bad, because these techniques may be used for destructive purposes. (h) Good, because pure water supply will improve the health of people. (i) Plastic surgery is something which cannot be classified as either good or bad. The technique helps to remove certain type of deformations in needy persons. But plastic surgery for cosmetic purposes is not good (j) Cloning is bad because it has the potential to destroy the normal family life of human society. |
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| 15. |
The dimensions of `(1)/(2) in_(0) E^(2)`, where `in_0` is permittivity of free space and E is electric field, is :-A. `[MLT^(-1)]`B. `[ML^(2)T^(-2)]`C. `[ML^(-1)T^(-2)] `D. `[ML^(2)T^(-1)]` |
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Answer» Correct Answer - C `(1)/(2) in_0 E^(2)` = Energy density = `("Energy")/("Volume")= [M^(1)L^(-1)T^(-2)]` |
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| 16. |
In dimension of circal velocity `v_(0)` liquid following through a take are expressed as `(eta^(x) rho^(y) r^(z))` where `eta, rhoand r `are the coefficient of viscosity of liquid density of liquid and radius of the tube respectively then the value of `x,y` and `z` are given byA. `1, 1, 1`B. `1, -1, -1`C. `-1, -1, 1`D. `-1, -1, -1` |
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Answer» Correct Answer - B `v_c prop [ eta ^(x) rho ^(y) r^(z)]` `[L^(1)T^(-1)] prop [M^(1)L^(-1) T^(-1)]^(x) [M^(1)L^(-3) ] ^(y) [L^(1)]^(z)` `[L^(1)T^(-1)] prop [ M^(x+y)] [ L^(-x + 3y+ z)] [ T^(-x)]` taking comparision on both size ` x+y =0, -x - 3y +z =1, -x =-1` `rArr x =1, y =-1, z=-1` |
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| 17. |
Write down the number of significant figures in the following. (a) 165 (b) 2. 05 (c ) 34.000 m (d) 0.005 (e) 0.02340 N `m^(-1)` (f) 26900 (g) 26900 kg |
| Answer» `{:((a), 165,,,3SF"(following rule I)"),((b),2.05,,,3SF"(following rules I & II)"),((c),34.000 m ,,,5SF"(following rules I & V)"),((d), 0.005,,,1SF"(following rules I & IV)"),((e),0.022340 N m^(-1),,,4SF"(following rules I, IV & V)"), ((f), 26900,,,3SF"(see rule VI)"), ((g),26900 kg,,,5SF"(see rule VI)"):}` | |
| 18. |
Which of the following has the highest number of significant figures ?A. `0.007 m^(2)`B. `2.64 xx 10^(24) kg `C. `0.0006032 m^(2)`D. `6.3200 J ` |
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Answer» Correct Answer - D According to the rules of significant figures `0.007 m^(2)` has one significant figures. `2.64 xx 10^(24) ` kg has three significant figures. `0.0006032 m^(2)` has four significant figures. `6.3200 J ` has five significant figures. |
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| 19. |
A student measures that distance traversed in free fall of a body, initially at rest in given time. He uses this data to estimated `g`, the acceleration due to gravity. If the maximum percentage error in measurement of the distance and the time are `e_(1)` and `e_(2)`, respectively, the percentage error in the estimation of `g` isA. `e_1 + 2e_2`B. `e_1+ e_2 `C. `e_1 - 2e_2 `D. `e_2 - e_1` |
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Answer» Correct Answer - A `h= (1)/(2) "gt"^(2) ` (for free fall) `g= (2h)/(t^(2)) rArr (Delta g)/(g) = (Delta h)/(h) + (2Delta t)/(t) = e_1 + 2e_2` |
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| 20. |
If the number of divisions on the circular scale is 100 and number of full rotations given to screw is 8 and distance moved by the screw is 4 mm, then what will be least count of the screw gauge ? |
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Answer» Correct Answer - 0.005 mm Pitch = `(4)/(8)`mm = 0.5 mm L.C. = `(0.5)/(100)` mm = 0.005 mm |
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| 21. |
Assertion : If we perform an experiment in our laboratory today and repeat the same experiment on the same objects under identical conditions after a year, the results are found to be the same . Reason : The laws of nature do not change with time.A. If both assertion and reason are true and reason is the correct explanation of assertion.B. If both assertion and reason are true but reason is not the correct explanation of assertion.C. If assertion is true but reason is false.D. If both assertion and reason are false. |
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Answer» Correct Answer - A Laws of nature like law of conservation of energy do not change with time. So reason is the correct explanation of assertion. |
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| 22. |
The dimensions of torque are :A. `[ML^(3)L^(-3)]`B. `[ML^(-1)T^(-1)]`C. `[ML^(2)T^(-2)]`D. `[ML^(-2)]` |
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Answer» Correct Answer - C Torque `vectau = vecr xx vecF` Dimensional for torque `vect= [L^(1)] [M^(1)L^(1) T^(-2)]` `" " = [M^(1)L^(2)T^(-2)]` |
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| 23. |
"Politics is the art of the possible'. Similarly, 'Science is the art of the soluble'. Explain this beautiful aphorism on the nature and practice of science. |
| Answer» Science is a systematised study of observations. A scientist patiently analyses these observation and comes out with certain laws. As an illustration, Tycho Brahe worked for twenty long years to make observations on planetary motions. It is from this huge reservoir of observations that Kepler formulated his three famous laws of planetary motion. Thus, science is the art of the soluble just as politics is the art of the possible. | |
| 24. |
"Every great physical theory starts as a heresy and ends as a dogma'. Give some examples from the history of science of the validity of this incisive remark. |
| Answer» A common observation in our daily life is that light travels in straight line. When Huygens propounded his wave theory, it was against the accepted belief. However, soon it became a dogma as reflection, refraction etc., could be successfully explained on the basis of wave theory. When photoelectric effect was discovered then it was found that wave theory of light cannot explain the phenomena and we came to a conclusion that light truely has dual characteristic. It may behave both as wave and a particle. We may consider other similar examples from the history of science. | |
| 25. |
Two physical quantities of which one is a vector and the other is a scalar having the same dimensional formula are :A. Work and energyB. Torque and workC. Impulse and momentumD. Power and pressure |
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Answer» Correct Answer - B |
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| 26. |
Which of the following is incorrect ?A. All derived quantities may be represented dimensionally in terms of the base quantitiesB. A base quantity cannot be represented dimensionally in terms of other base quantitiesC. The dimension of a derived quantity is never zero in any base quantityD. The dimension of a base quantity in other base quantities is always zero. |
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Answer» Correct Answer - C |
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| 27. |
Which of the following quantity is unitless ?A. Velocity gradientB. Pressure gradientC. Displacement gradientD. Force gradient |
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Answer» Correct Answer - C Velocity gradient `=(m//s)/( m) = s^(-1)` Pressure gradient `=(kg //mxs^(2))/( m) = (kg)/(m^(2) xx s^(2))` Displacement gradient `= (m)/(m)` = unitless Force gradient `= (kg xx m//s^(2))/(m) = kg//s^(2)` |
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| 28. |
Pick out the correct statements about the strong nuclear force from the following. `S1: It is charge independent. S2: It is the strongest force in nature. S3: Its range is very large. S4: It is responsible for the stability of nuclei.A. S1 and S3B. S1, S2 and S3C. S1, S2 and S4D. S2 and S3 |
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Answer» Correct Answer - C The range of strong nuclear force is very small, og about nuclear dimensions `(10^(-15)m)`. |
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| 29. |
Force of friction and tension in a string areA. Gravitational forcesB. Electromagnetic forcesC. Nuclear forcesD. Weal forces |
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Answer» Correct Answer - B Force of friction and tension in a string are electromagnetic forces. |
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| 30. |
Assertion : The elastic spring force arises due to the net attraction or repulsion between the neighbouring atoms of the spring when it is elongated of compressed. Reason : The laws of derived forces such as spring force, friction force are independent of the laws of fundamental forces in nature.A. If both assertion and reason are true and reason is the correct explanation of assertion.B. If both assertion and reason are true but reason is not the correct explanation of assertion.C. If assertion is true but reason is false.D. If both assertion and reason are false. |
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Answer» Correct Answer - C The laws of derived forces such as spring force, friction are not independent of the laws of fundamental forces in nature. So the reason is false. |
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| 31. |
Generation, propagation and detection of electromagnetic waves is the basis ofA. lasersB. reactorsC. radio and televisionD. computer |
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Answer» Correct Answer - C Generation, propagation and detection of electromagnetic waves is the basis of radio and television. |
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| 32. |
What is the discovery of `CV` Raman?A. Inelastic scattering of light by moleculesB. Steam engineC. Propagation of `EM` waveD. Reflection of Ultrasonic waves |
| Answer» Correct Answer - A | |
| 33. |
What is the contribution of `S`.Chandra Sekher to physics?A. cosmic radiationB. Nuclear model & atomC. `LASER`D. Structure and evolution of stars |
| Answer» Correct Answer - D | |
| 34. |
Physics involves the study ofA. plantsB. humansC. birds and animalsD. nature and natural phenomena |
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Answer» Correct Answer - D Physics is a branch of science which deals with the study of nature and natural phenomena. |
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| 35. |
Which of the following is smallest unitA. Millimetre B. AngstromC. FermiD. Metre |
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Answer» Correct Answer - C |
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| 36. |
`{:(,"Column I",,"Column II"),((A),"Dimensional variable",(p),pi),((B),"Dimensionless variable",(q),"Force"),((C),"Dimensional constant",(r),"Angle"),((D),"Dimensionless constant",(s),"Gravitational constant"):}` |
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Answer» Correct Answer - (i) (b), (ii) (c ), (iii) (d), (iv)(a) |
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| 37. |
The range of masses we study in Physics isA. `10^(-27) kg` to `10^(60) kg`B. `10^(-27) kg` to `10^(55) kg`C. `10^(-30)kg` to `10^(55) kg`D. `10^(-30) kg` to `10^(60) kg` |
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Answer» Correct Answer - C The range of masses goes from `10^(-30)kg` (mass of an electron)to `10^(55) kg` (mass of known observable universe). |
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| 38. |
It is often said that the world is witnessing now a second industrial revolution, Which will transform the society as radically as did the first. List some key contemporary area of science and technology, which are responsible for this revolution. |
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Answer» Some key contemporary areas of science and technology, which are chiefly responsible for a new industrial revolution taking place now and likely to take place in near future are: (i) Design of super-fast computers. Biotechnology. Developments in the field of space sciences. Development of super-conducting materials at room temperature. Advancements in the fields of electronics, information technology and nanotechnology. |
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| 39. |
Which of the following is smallest unitA. MillimetreB. AngstromC. FermiD. Metre |
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Answer» Correct Answer - C |
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| 40. |
Which of the following system of units is not based on units of mass, length and time alone ?A. SIB. MKSC. FPSD. CGS |
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Answer» Correct Answer - A |
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| 41. |
A spherometer has 250 equal divisions marked along the periphery of its disc, and one full rotation of the disadvances by 0.0625 cm on the main scale. What is the least count of the spherometer ? |
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Answer» Correct Answer - `2.5 xx 10^(-4)` cm L.C. = `(0.0625)/(250)` cm = `2.5 xx 10^(-4)` cm |
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| 42. |
A physical quantity x is calculated from the relation `x = a^(3)b^(2)//sqrt(cd)`. Calculate percentage error in x, if a, b, c and d are measured respectively with an error of 1 %, 3 %, 4% and 2%. |
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Answer» Correct Answer - `pm 12% ` `x = (a^(3) b^(2))/( sqrt(cd))` `(Delta x)/(x) = 3 (Delta a)/(a) + 2 (Delta b)/(b) + (1)/(2) (Delta c)/(c ) + (1)/(2) (Delta d)/(d)` `(Delta x)/(x) xx 100 = 3 xx 1 + 2 xx 3 + 4 xx 1//2 + 2 xx 1//2` `" " = 12% ` |
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| 43. |
The least count of a stop watch is `(1//5)s`. The time 20 oscillations of a pendulum is measured to be `25 s`. The maximum percentage error in this measurement is |
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Answer» Error in measuring 25 s `= (1)/(5) s = 0.2` sec. `" "therefore ` percentage error = `(0.2)/(25)xx 100= 0.8` % The final absolute error in this type of questions is taken to be equal to the least count of the measurement intrument. |
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| 44. |
The resistance `R = V//i`, where `V = 100 +- 5 V and I = 10+- 0.2 A`. What is the total error in `R`?A. `5%`B. `7%`C. `5.2%`D. `((5)/(2))%` |
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Answer» Correct Answer - B `R= (V)/(I) rArr (Delta R)/(R ) = (Delta V)/(V) + (Delta I)/(I)` `rArr (Delta R)/(R ) xx 100 = ((5)/(100)xx 100 + (0.2)/(10) xx 100) = 7%` |
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| 45. |
If dimensions of A and B are different, then which of the following operaion is valid ?A. `(A)/(B)`B. `e^(-A//B)`C. `A-B`D. `A+B` |
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Answer» Correct Answer - A |
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| 46. |
The centripetal force F acting on a particle moving uniformly in a circle may depend upon mass (m), velocity (v) and radius ( r) of the circle . Derive the formula for F using the method of dimensions. |
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Answer» Correct Answer - `F= K (mv^(2))/(r )` `F prop m^(a) v^(b)r^(c ) rArr F = km^(a) v^(b) r^(c ) ` `rArr [M^(1)L^(1) T^(-2)] = [M]^(a) [ L^(1)T^(-1)]^(b) [L]^(c ) = [M]^(a) [L]^(b+c) [T]^(-b) ` by comparision a = 1, b = 2, c= -1 So `F= k(mv^(2)) /(r )` |
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| 47. |
What is the working principle of Steam engine?A. Digital logicB. Super conductivityC. Laws of thermodynamicsD. Nuclear fission |
| Answer» Correct Answer - C | |
| 48. |
Lightning was discovered byA. OhmB. ThomsonC. FranklinD. Faraday |
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Answer» Correct Answer - C Lighting was discovered by Franklin. |
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| 49. |
Who discovered neutron?A. James chandwickB. FermiC. S.N. BoseD. Millikan |
| Answer» Correct Answer - A | |
| 50. |
Percentage error in measuring the radius and mass of a solid sphere are 2 % & 1 % respectively. The error in measurement of moment of inertia about to its diameter is :-A. `3% `B. `6%`C. `5%`D. `4%` |
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Answer» Correct Answer - C `I = 2//5 MR^(2)` `(Delta I)/(I) = (Delta M)/(M) + 2(Delta R)/(R )` `(Delta I)/(I) xx 100 = 1 % + 2 xx 2% = 5%` |
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