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. |
Which of the following is a sedimentary rock?1. Anthracite2. Granite3. None4. Quartzite |
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Answer» Correct Answer - Option 1 : Anthracite The correct answer is Anthracite.
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| 2. |
Who built the Rani Mahal and Chaman Mahal in Islamnagar?1. Sultan Muhammad Khan2. Nizam Shah3. Dost Mohammed Khan4. Yar Mohammad Khan |
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Answer» Correct Answer - Option 3 : Dost Mohammed Khan The correct answer is Dost Mohammed Khan.
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| 3. |
Statement : The meteorological department has predicited normal rainfall throughout the country during the current monsoon. Courses of action : I. The government should reduce the procurement price of food grains for the current year. II. The government should reduce subsidy on fertilizers for the current year.A. If only course of action I followsB. if only coruse of action II followsC. if either course of action I or II follows.D. if neither course of action I nor II follows. |
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Answer» Correct Answer - D Both the course of action are not suitable because when there is no problem , no action is required . |
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| 4. |
A rainy day as defined by the Indian Meteorological department is a day when the rainfall at a point received is (a) 0.5 mm to 1 mm in 24 hours (b) 1.1 mm to 1.5 mm in 24 hours (c) 1.6 mm to 2 mm in 24 hours (d) above 2.5 mm in 24 hours |
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Answer» (d) above 2.5 mm in 24 hours |
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| 5. |
Soil of Western Rajasthan have a high content or (a) Aluminium (b) Calcium (c) Nitrogen (d) Phosphorus |
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Answer» Soil of Western Rajasthan have a high content or Calcium. |
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| 6. |
Which of the following highway networks of India connects Delhi , Mumbai , Kolkata and Chennai ?A. Metro ExpresswayB. Golden QuadrilateralC. Diamond TriangleD. Golden Crescent |
| Answer» Correct Answer - B | |
| 7. |
How is oxygen and CO2 transported in human beings? |
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Answer» During respiration, about 97% of oxygen is transported by RBC’s by forming oxyhaemoglobin and the remaining 3% gets dissolved in the plasma. Since haemoglobin pigment has less affinity for CO2, it is mainly transported in the dissolved form. Around 20 -25% of CO2 is carried by haemoglobin as carbamino-haemoglobin, 7% is in a dissolved state in the plasma and the remaining is carried as bicarbonate. This deoxygenated blood gives CO2 to lung alveoli. |
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| 8. |
Which of the following options prove that India is a quasi-federal state? I. More powers with Centre II. Residuary subjects with Centre III. Equal subjects with Centre and States IV. Currency and Railways with CentreA. I, III & IV B. I, II & IV C. II, III & IV D. II, III & IV |
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Answer» Option : B. I, II & IV |
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| 9. |
Choose the correct answer:The appointment of Lok Aykta at the state level was first recommended by1. Rajasthan State Administrative Reforms Committee2. Administrative Reforms Commission of India (1966-70)3. Second Administrative Reforms Commission4. Sathanam Committee |
Answer» Correct Answer - Option 2 : Administrative Reforms Commission of India (1966-70)
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| 10. |
As per year Statistical Review of World Energy 2015, India is the ______ largest producer of coal in the world.1. 1st2. 4th3. 6th4. 8th |
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Answer» Correct Answer - Option 2 : 4th The correct answer is 4th.
Depending upon the quantity of carbon % coal are of four types:
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| 11. |
Which of the following trees will you find in the Littoral forests?1. Ebony2. Sundari3. Cypress4. Chinar |
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Answer» Correct Answer - Option 2 : Sundari The Correct Answer is Sundari.
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| 12. |
A solenoid of resistance R and inductance L has a piece of soft iron inside it. A battery of emf E and of negligible internal resistance is connected across the solenoid as shown in Fig. At any instant, the piece of soft iron is pulled out suddenly so that inductance of the solenoid decrease to `etaL(eta lt 1)` with battery remaining connected. Assume t = 0 is the instant when iron piece has been pulled out, the current as a function of time after this isA. `i=E/R [1-(1-(1)/(eta))e^(-t/(lambda))]`B. `i=E/R [1+(1+(1)/(eta))e^(-t/(lambda))]`C. `i=E/R [1-(1+(1)/(eta))e^(-t/(lambda))]`D. `i=E/R [1+(1-(1)/(eta))e^(-t/(lambda))]` |
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Answer» Correct Answer - A As current increase on pulling out the iron piece, the current will decrease to achieve its steady state value `E//R` again. At any time: `E=IR+etaL(dI)/(dt)implies int_(I_2)^(i) (dI)/(E-IR)= int_(0)^(t)(dt)/(etaL)` Solve to get: i=(E)/(R)[1-(1-(1)/(eta))e^(-t//lambda)]`. |
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| 13. |
A solenoid of resistance R and inductance L has a piece of soft iron inside it. A battery of emf E and of negligible internal resistance is connected across the solenoid as shown in Fig. At any instant, the piece of soft iron is pulled out suddenly so that inductance of the solenoid decrease to `etaL(eta lt 1)` with battery remaining connected. Power supplied by the battery as a function of timeA. `P=(E^(2))/R [1+(1-(1)/(eta))e^(-t/(lambda))]`B. `P=(E^(2))/R [1+(1+(1)/(eta))e^(-t/(lambda))]`C. `P=(E^(2))/R [1-(1+(1)/(eta))e^(-t/(lambda))]`D. `P=(E^(2))/R [1-(1-(1)/(eta))e^(-t/(lambda))]` |
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Answer» Correct Answer - D `P=Ei=(E^2)/(R)[1-(1-(1)/(eta))e^(-t//lambda)]` |
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| 14. |
Statement-1: ` sum_(r =0)^(n) (r +1)""^(n)C_(r) = (n +2) 2^(n-1)` Statement -2: ` sum_(r =0)^(n) (r+1) ""^(n)C_(r) x^(r) = (1 + x)^(n) + nx (1 + x)^(n-1)`A. STATEMENT - 1 is True, STATEMENT - 2 is True and STATEMENT - 2 is correct explanation for STATEMENT - 1.B. STATEMENT - 1 is True, STATEMENT - 2 is True and STATEMENT - 2 is NOT correct explanation for STATEMENT - 1.C. STATEMENT-1 is True, STATEMENT-2 is FalseD. STATEMENT-1 is False, STATEMENT-2 is True |
| Answer» Correct Answer - A | |
| 15. |
Let `n` be a positive integer if `1le1gt K len` such that `(sin^(2)nx)/(sin^(2)x)=a_(@)+sum_(1ge i lt klen) a_(1,k) cos 2 (k-1)` for all real number `x` with `x` not an integer multiple of `pi`, then the value of `a_(1,k)` is |
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Answer» Correct Answer - 2 `s=sin2x+sin4x+……+sin2nx` `=(sin nx-sin(n+1)x)/(sinx)` `c=cos2x+cos4c+………..+cos2nx` `=(sin nx cos (n+1)x)/(sinx)` `((sin^(2)nx)/(sin^(2)nx))^(2)=((sin n xsin(n+1)x)/(sinx))^(2)+((sin n cos(n+1)x)/(sinx))^(2)=s^(2)+c^(2)` On the other hand `s^(2)+c^(2)=(sin2x+sin4x+...........sin2nx)^(2)+(cos2x+cos4x+.............+cos2nx)^(2)` `=n+sum_(1le 1lt k le n) (2sin 2 xsin 2 kx +2cos 2 x cos 2kx)` `=nn+2 sum_(1le 1 lt k le n)cos2(k-1)x` `implies a_(1,k)=2` |
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| 16. |
A tosses `2` fair coins & `B` tosses 3 fair cons after game is won by the person who throws greater number of heads. In case of a tie, the game is continued under identical rules until someone finally wins the game. The probability that A finally wins the game is `K//11`, then `K` is |
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Answer» Correct Answer - 3 `A_(i)=` no. of heads obtained by `A` when tosses two coins `B_(i)=` no of heads obtained by `B` when tosses `3` coins `P(E)=P{(A_(1)nnB_(0))uu(A_(2)nnB_(2))uu(A_(2)nnB_(1))}` `=2C_(1)(1/2)(1/2)(1/2)^(3)+(1/2)^(2)+(1/2)^(2)3C_(1)(1/2)(1/2)^(2)` `=2/32+1/32+3/32=3/36` `F={A` & `B` tie a particular game `}` then`P(F)=P{(A_(0)nnB_(0))uu(A_(1)nnB_(1))uu(A_(2)nnB_(2))}=5/16` `P` (`A` finally wins the game ) `=P(E` or `FE` or `FFE` or ........) `=3/11` |
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| 17. |
What is rabi season? |
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Answer» The cropping season in which the cultivation is started by the beginning of winter and harvested by the beginning of summer. |
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| 18. |
Which of the following is a rabi crop? (a).Pulses (b).Cotton (c).Jute (d).Maize |
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Answer» Option : (a).Pulses |
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| 19. |
Laterite soil which is generally not suitable for other crops is good for the cultivation of (a).Sugarcane (b).Coffee (c).Rubber (d).Jute |
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Answer» Option : (c).Rubber |
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| 20. |
Which one of the following straits is nearest to the International Date Line? (a) Malacca Strait (b) Bering Strait (c) Strait of Florida (d) Strait of Gibraltar |
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Answer» (b) Bering Strait is nearest to the International Date line, because the international Date line runs equidistant between the American continents, on its East and Asia, Australia, and Europe on its west. |
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| 21. |
Study the following diagrams, A and B.(a) A is cyclone in the southern hemisphere(b) A is an anti-cyclone in the southern hemisphere(c) B is a cyclone in the northern hemisphere(d) B is an anti-cyclone in the northern hemisphere |
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Answer» (c) B is a cyclone in the northern hemisphere |
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| 22. |
"I take holy vows in the name of God and say that I will continue to fight for the freedom of India and its thirty-eight crores inhabitants till my last breath." Who made this statement?1. Bhagat Singh2. Subhash Chandra Bose3. Mahatma Gandhi4. Lala Lajpat Rai |
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Answer» Correct Answer - Option 3 : Mahatma Gandhi The correct answer is Mahatma Gandhi.
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| 23. |
Which of the following was not a part of Napoleon’s defeat?A. BritainB. AustriaC. ItalyD. Germany |
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Answer» C.Italy is the place which was not a part of Napoleon's defeat.
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| 24. |
Explain the performance enhancing substance in detail. |
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Answer» Performance-enhancing substances (PESs) are used commonly by children and adolescents in attempts to improve athletic performance. More recent data reveal that these same substances often are used for appearance-related reasons as well. PESs include both legal over-the-counter dietary supplements and illicit pharmacologic agents. This report reviews the current epidemiology of PES use in the pediatric population, as well as information on those PESs in most common use. The performance enhancing substances are as follows: The use of drugs to enhance performance is considered unfair and puts the health of athlete at high risk like (a) Mechanical aids :- It includes altitude training, aqua training, elastic cord, treadmills, vibration training, weight training etc. (b) Pharmacological aids :- It includes Anabolic steriod, beta blockers, caffeine, choline, sodium bicarbonate. These are all banned by IOC in sports. (c) Physiological aids :- It includes Herbal medicines, sports massage, sauna, Human Growth hormones. (d) Nutritional aids :- They are like Bicarbonate of soda, carbohydrate loading, creatine, sports drinks. (e) Psychological aids :- These includes mediation, motivation, centering, cheering, Relaxation. Most of these are valid and applicable in sports. |
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| 25. |
Solve by the method of variation of parameters y'' - 4y' + 4y = x-1 e2x. |
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Answer» Given differential equation is y'' - 4y' + 4y = \(\frac{e^{2x}}x\) It's auxiliarly equation is m2 - 4m + 4 = 0 ⇒ (m - 2)2 = 0 ⇒ m - 2 = 0 ⇒ m = 2, 2 \(\therefore\) w(y1, y2) = \(\begin{vmatrix}y_1&y_2\\y'_1&y'_2\end{vmatrix}\) = \(\begin{vmatrix}e^{2x}&xe^{2x}\\2e^{2x}&(2x+1)e^{2x}\end{vmatrix}\) = (2x + 1 - 2x)e4x = e4x u1 = \(\int\cfrac{\begin{vmatrix}0&xe^{2x}\\ \frac{e^{2x}}x&(2x+1)e^{2x}\end{vmatrix}}{w(y_1y_2)}dx\) \(=\int\frac{-e^{4x}}{e^{4x}}dx=-x\) u2 = \(\int\cfrac{\begin{vmatrix}e^{2x}&0\\ 2e^{2x}&\frac{e^{2x}}x\end{vmatrix}}{w(y_1y_2)}dx\) = \(\int\frac{e^{4x}}{x.e^{4x}}dx\) = \(\int\frac1{x}dx=log x\) \(\therefore\) P.I. = u1y1 + u2y2 = -xe2x + xe2xlog x \(\therefore\) Complete solution is y = C.F. + P.I. = (C1 + C2x)e2x - xe2x + xe2x log x |
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| 26. |
Solve `x^(2)(d^(2)y)/(dx^(2))+x(dy)/(dx)-y=(x^(3))/(1+x^(2))` |
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Answer» Given differential equation is \(x^2\frac {d^2y}{dx^2} + x\frac {dy}{dx} -y = \frac {x^3}{1+x^2}\) Then \(x \frac {dy}{dx} = \frac {dy}{dz} = dy\), where D = \(\frac {y}{dz}\) \(x^2 \frac {d^2y}{dx^2} \) = D (D-1) y. Then given differential equation converts to D(D-1)y + Dy-y = \(\frac {e^{3z}}{1+e^{2z}}\) = (D2 - D + D-1)y = \(\frac {e^{3z}}{1+e^{2z}}\) = (D2 -1)y = \(\frac {e^{3z}}{1+e^{2z}}\) It's auxiliarly equation is m2-1 = 0 = m = ± 1 ∴ C.F = C1 e-z+ C2 ez = \(\frac {C_1}{x} + C_2 x\) (∵ez = x) Let y1 = \(\frac 1x\) & y2 = x ∴ W(y1, y2) = \(\begin {vmatrix}y_1&y_2\\y_1^1&y_2^1\end {vmatrix} = \begin {vmatrix}\frac 1x&x\\\frac {-1}{x^2}&1\end {vmatrix}\) = \(\frac1x + x . \frac {1}{x^2} = \frac 1x + \frac 1x = \frac 2x\) ∴ y1 =\(\int\) \(\frac {\begin {vmatrix}0&x\\\frac {x^3}{1+x^2}&1\end{vmatrix}}{W(y_1,y_2)}dx\) = \(\int \frac {-\frac {x^4}{1+x^2}}{\frac 2x}dx\) = \(\frac {-1}{2}\int \frac {x^5}{1+x^2}dx = \frac {-1}{2} \int (x^3-x+\frac {x}{1+x^2})dx\) = \(\frac {-1}{2}(\frac {x^4}{4} - \frac {x^2}{2} + 12 log (1 +x^x2))\) & y2 = \(\int \frac {\begin {vmatrix}\frac 1x&0\\\frac {-1}{x^2} & \frac {x^3}{1+x^2}\end {vmatrix}}{W (y_1,y_2)}\) = \(\int \frac {\frac {x^2}{1+x^2}}{\frac 2x}dx = \frac 12\int\frac {x^3}{1+x^2}dx\) = \(\frac 12 \int (x- \frac {x}{1+x^2})dx\) = \(\frac 12(\frac {x^2}{2} - \frac 12 log (1+x^2))\) ∴ P.I = y1y1 + y2y2 = \(\frac {-1}{2x} (\frac {x^4}{4} - \frac {x^2}{2} + \frac 12 log (1+x^2)) + \frac x2 (\frac {x^2}{2} - \frac 12 log (1+x^2))\) = \(\frac {-x^3}{8} + \frac x4 - \frac {1}{4x}log (1+x^2) + \frac {x^3}{4} - \frac x4 log (1+x^2)\) = \(\frac {x^3}{8} + \frac x4 - \frac x4log (1+x^2) \frac {-1}{4x}log (1+x^2)\) ∴ Complete solution is y = C.F + P.I = \(\frac {C_1}{x} + C_2x + \frac {x^3}{8} + \frac x4 - \frac x4 log (1+x^2) - \frac {1}{4x} log (1+x^2)\) |
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| 27. |
Solve by the method of undermined coefficients y'' - 6y' + 9y = 4ex. |
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Answer» Given differential equation is y11 - 6y1 + 9y = 4ex It's auxiliarly equation is m2 - 6m + 9 = 0 ⇒ (m - 3)2 = 0 ⇒ m = 3, 3 \(\therefore\) C.F. = (C1 + C2x)e3x Let y1 = xe3x, y2 = e3x \(\therefore\) w(y1,y2) = \(\begin{vmatrix}xe^{3x}&e^{3x}\\e^{3x}(3x + 1)&3e^{3x}\end{vmatrix}\) = e6x(3x - 3x - 1) = -e6x \(\therefore\) u1 = \(\int\cfrac{\begin{vmatrix}0&e^{3x}\\4e^x&3e^{3x}\end{vmatrix}}{w(y_1y_2)}dx\) = \(\int\frac{-4e^{4x}}{-e^{6x}}dx\) = 4\(\int e^{-2x}dx\) = \(\frac{4e^{-2x}}{-2}\) = -2e-2x = 2xe-2x + e-2x = (2x + 1)e-2x \(\therefore\) P.I. = u1y2 + u2y2 = -2e-2x x xe3x + (2x + 1)ex = ex \(\therefore\) Complete solution is y = C.F. + P.I. = (C1 + C2x)e3x + ex |
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| 28. |
When 1231, 1471, and 1711 are divided by the greatest number a, then, the remainder in each case is b. Then, what is the value of (a - b)?1. 2492. 2603. 3004. 209 |
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Answer» Correct Answer - Option 4 : 209 We need to find the Greatest Common Factor (HCF). Thus, (1471 – 1231) = 240 (1711 - 1471) = 240 (1711 – 1231) = 480 = 2 × 240 Therefore, The greatest number is 240. So, Numbers are – 1231 = (240 × 5) + 31 1471 = (240 × 6) + 31 1711 = (240 × 7) + 31 The remainder is 31. According to question – ⇒ (a – b) = 240 – 31 = 209 |
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| 29. |
Ishq Marathi bhasha kaise karen |
| Answer» मला वाटतं उत्तर असेल इश्क | |
| 30. |
When four positive numbers a, b, c, and d are divided by 41, the remainders are 3, 4, 6, and 2, respectively. When (5a + 6b – 2c + 10d) is divided by 41, then, the remainder will be – 1. 52. 73. 64. 17 |
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Answer» Correct Answer - Option 3 : 6 GIVEN: When four positive numbers a, b, c, and d are divided by 41, the remainders are 3, 4, 6, and 2, respectively. CONCEPT: Dividend = Divisor x Quotient + Remainder CALCULATION: a = 41w + 3, b = 41x + 4, c = 41y + 6, d = 41z + 2 Here, 41w, 41x, 41y and 41z is divisible by 41. So, according to question – (5a + 6b – 2c + 10d) ⇒ (15 + 24 – 12 + 20) ⇒ 59 – 12 ⇒ 47 When (5a + 6b – 2c + 10d) is divided by 41. ⇒ Remainder (47/41) = 6 |
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| 31. |
Which measure did the villagers not adopt to defend themselves against the tiger? (a) they kept the bonfire up all night (b) they posted armed vigilant guards (c) they scattered poisoned meat for tiger (d) they tethered a lamb to the outskirts of the village. |
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Answer» Correct answer is (d) they tethered a lamb to the outskirts of the village. |
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| 32. |
‘A more slothful creature was never created. All his energy is conserved for hunting food…’ Who are these lines referring to? (a) the tiger (b) the lion (c) the mighty Python (d) the great Hunter |
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Answer» Correct answer is (b) the lion |
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| 33. |
If you want to see monkeys, lions, tigers and bears, you would go to the ___. |
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Answer» Correct answer is zoo |
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| 34. |
Running, playing tennis, and other sports are part of ___ |
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Answer» Correct answer is Physical education |
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| 35. |
A place where famous paintings and sculptures are kept and displayed to the public is called an _ |
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Answer» Correct answer is art museum |
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| 36. |
Find the co-ordinates of the point where the line through the points A(3, 4, 1) and B(5, 1, 6) crosses the xy -plane. |
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Answer» The Cartesian equation of line passing through two points A(3, 4, 1) and B(5, 1, 6) is \(\frac{x -3}{5-3} = \frac{y-4}{1-4} = \frac{z-1}{6-1} = \frac{y-4}{-3} = \frac{z - 1}{5}\). (By Cartesian equation of line passing through two points) Since, the line passes through points A (3,4,1) and B (5,1,6) crosses the xy - plane. Hence, z - coordinates of line is zero. Therefore, \(\frac{x-3}{2} = \frac{y-4}{-3} = \frac{0-1}{5} = -\frac{1}{5}\) ⇒ \(\frac{x-3}{2} = -\frac{1}{5}\) and \(\frac{y-4}{-3} = -\frac{1}{5}\). ⇒ x = \(-\frac{2}{5} + 3\) and y = \(\frac{3}{5} + 4 = \frac{23}{4}\). Therefore, the co-ordinates of the point is \((\frac{13}{5}, \frac{23}{5},0)\) Hence, the co-ordinates of the point where the line through the points A(3,4,1)and B(5,1,6) crosses the xy - plane is \((\frac{13}{5}, \frac{23}{5},0)\). |
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| 37. |
Find the number of prime factors of 10010.1. 42. 63. 54. 7 |
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Answer» Correct Answer - Option 3 : 5 Prime factors of 10010 = 2 × 5 × 7 × 11 × 13. So, the number of prime factors is 5. |
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| 38. |
If the points C and D represent real number 0.43333… and 0.7666… on the number line. Then, find the difference between C and D.1. 12/72. 1/33. 13/194. 27/9 |
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Answer» Correct Answer - Option 2 : 1/3 Concept Value of 0.333… = 3/9 Value of 0.66… = 6/9 Explanation Value of 0.4333…. Let x = 0.4333… ----(1) Multiply 0.4333… by 10 10x = 4.333…. ----(2) Subtract (1) from (2) ⇒ 10x – x = 4.333… - 0.4333… ⇒ 9x = 3.9 ⇒ x = 39/90 ----(A) Value of 0.7666…. Let y = 0.7666…. ----(3) Multiply 0.766… by 10 ⇒ 10y = 7.6666 ----(4) Subtract (3) from (4) ⇒ 10y – y = 7.666… - 0.7666 ⇒ 9y = 6.9 ⇒ y = 69/90 ----(B) Difference of (A) and (B) ⇒ (69/90) – (39/90) ⇒ 30/90 ⇒ 1/3 |
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| 39. |
Square of 0.02 is _____?1. 0.042. 0.00043. 0.14. 0.24 |
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Answer» Correct Answer - Option 2 : 0.0004 Here, we have to find the square of 0.02 Calculation: (0.02)2 ⇒ (2/100)2 ⇒ 4/10000 ⇒ 0.0004 Hence, the square of 0.02 is 0.0004. |
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| 40. |
Which of the following statements is not correct?1. Difference of squares of two odd numbers is odd.2. We can express 30 as n × (n + 1) × (n + 3), where n is a natural number.3. 3/4 < 219/2921. Statement 1 and Statement 2 are not correct2. Statement 2 and Statement 3 are not correct3. Statement 1 and Statement 3 are not correct4. All are correct |
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Answer» Correct Answer - Option 3 : Statement 1 and Statement 3 are not correct Concept used: Product of two odd natural numbers is always odd. Difference and sum of two odd numbers is always even. Calculation: Statement 1: Let x and y be two odd numbers As, product of two odd numbers is always odd ⇒ x2 is odd ⇒ y2 is odd |x2 – y2| is even, because difference of two odd numbers is always even. Hence, Statement 1 is not correct Statement 2 We can express 30 as 2 × 3 × 5 ⇒ 30 = 2 × (2 + 1) × (2 + 3) For n = 2, 30 can be expressed as n × (n + 1) × (n + 3) Hence, Statement 2 is correct Statement 3 3/4 = (3 × 73/(4 × 73) = 219/292 Hence, Statement 3 is not correct ∴ Statement 1 and Statement 3 are not correct |
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| 41. |
A three-digit number is such that when its reverse is subtracted from it, the result is 396. Also, the tens digit is equal to the average of its hundreds and units digits. How many possible values are there for the number?1. 72. 63. 54. 4 |
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Answer» Correct Answer - Option 2 : 6 Let’s assume a, b, c be the hundreds, tens and units digits of the desired number. So, the desired number ‘abc’ = 100a + 10b + c After reversing it, it becomes ‘cba’ = 100c + 10b + a Now, ‘abc’ – ‘cba’ = (100a + 10b + c) - (100c + 10b + a) ⇒ 396 = 99(a – c) ⇒ (a – c) = 396/99 = 4 Thus, possible combination of (a, c) = {(9, 5), (8, 4), (7, 3), (6, 2), (5, 1), (4, 0)} For every combination of (a, c) only one value of b is possible.
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| 42. |
If y = sin(x3) then dy/dx = (A) x3cos(x3) (B) 3x2 sin(x3) (C) 3x2 cos(x3) (D) cos(x3) |
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Answer» correct option: (B) 3x2 sin(x3) |
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| 43. |
If x = at2, y = 2at then dy/dx = (A) t(B) 1/t(C) at(D) a/t |
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Answer» correct option: (B) 1/t |
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| 44. |
If A = |(3, 1),(-1, 2)| then A2 – 5A + 7I is(A) Diagonal matrix(B) Identify matrix(C) zero matrix(D) None of these |
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Answer» (A) Diagonal matrix |
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| 45. |
Which of the examples below expresses the commutative law of multiplication. A. A+B=B+A B. AB=B+A C. AB=BA D. AB=A*B |
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Answer» Correct option is: C. AB=BA |
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| 46. |
-If `a,b,c in R` then prove that the roots of the equation `1/(x-a)+1/(x-b)+1/(x-c)=0` are always real cannot have roots if `a=b=c`A. One roots lies in (a,b)B. One root lies in (b,c)C. One root must be non-realD. Three roots are real. |
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Answer» Correct Answer - A::B::D Simplifying `x(x-b)(x-c)+x(x-c)(x-a)+x(x-a)(x-b)-(x-a)(x-b)(x-c)=0` let `f(x)=x(x-b)(x-c)+x(x-c)(x-a)+x(x-a)(x-b)-(x-a)(x-b)(x-c)` `becausef(a)=a(a-b)(a-c)gt0` `f(b)=b(b-c)(b-a)gt0` `f(x)=c(c-a)(c-b)gt0` (assuming `altbltc)` If two roots are real, then the polynomial of degree three has the third root which must be real. |
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| 47. |
A line `L` is perpendicular to the curve `y= (x^2) / 4 - 2` at its point `p` and passes through `(0, -1)`. The coordinates of the point p areA. `( 2 , -1)`B. (6 , 7)C. `(0 , -2)`D. (4 , 2) |
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Answer» Correct Answer - D Let the point is `(h , (h^(2) - 8)/(4))` , equation of normal `( y (h^(2) - 8)/( 4)) = (-2)/(h) (x - h)`, `because (10 , -1)` lies on it `h^(3) + 4h - 80 = 0` |
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| 48. |
If the point \( (2 \alpha, 3 \alpha) \) lies inside the ellipse \( \frac{x^{2}}{4}+\frac{y^{2}}{9}=1 \), then complete set of values of \( \alpha \) is(A) \( \alpha \in(-\infty,-1) \cup(1, \infty) \) (B) \( \alpha \in(-1,1) \)(C) \( \alpha \in(-1,3) \)(D) \( \alpha \in\left(\frac{-1}{\sqrt{2}}, \frac{1}{\sqrt{2}}\right) \) |
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Answer» Option (D) is correct. Given that point (2α, 3α) lies inside the ellipse \(\frac{x^2}{4} + \frac{y^2}{9} = 1.\) Therefore, \(\frac{(2 \alpha)^2}{4} + \frac{(3 \alpha)^2}{9} < 1\) \(\Rightarrow\) α2 + α2 < 1 \(\Rightarrow\) 2α2 < 1 \(\Rightarrow\) α2 < \(\frac{1}{2}\) \(\Rightarrow\) α ∈ \(\left(-\frac{1}{\sqrt{2}}, \frac{1}{\sqrt{2}} \right)\) |
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| 49. |
5. \( \quad|2 x-1|=|x|+|x-1| \) holds for :(A) \( (-\infty, 0] \cup[1, \infty) \)(B) \( (0, \infty) \)(C) \( R \) |
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Answer» \(|2x - 1| = |x| + |x - 1|\) holds for \(x\in [-\infty , 0] \cup [1, \infty)\) \(\therefore |2x - 1| = |x + (x - 1)|\) \(\le |x| + |x - 1|\) But equality holds for \(x\in(\infty, 0] \cup [1, \infty)\) Alternatively: Case I: \(x \in (-\infty, 0]\) Then |x| = -x & \(|x - 1| = -(x - 1)\) Also \(|2x - 1| = -(2x - 1)\) \(\because -(2x - 1) = -2x + 1 = - x - x + 1 = -x -(x - 1)\) ⇒ \(|2x - 1| = |x | + |x - 1| \) given equality holds. Case II: \(x\in \left(0, \frac 12\right)\) Then \(|x| = x\) \(|x - 1| = -(x - 1) = 1 - x\) \(|2x - 1| = -(2x - 1)\) \(\because |2x -1| = -(2x - 1) = 1- 2x = 1 -x - x \) \(= |x - 1| - |x|\) given equality not hold Case III: \(x\in\left(\frac 12 , 1\right)\) Then \(|x| = x\) \(|x - 1| = -(x - 1) = 1 -x\) \(|2x - 1| = 2x - 1\) \(\because |2x- 1| = 2x - 1 = x + x - 1 =|x| - (1 -x)\) \(=|x| - |x - 1|\) given inequality not hold. Case IV: \(x\in[1, \infty)\) Then \(|x| = x\) \(|x - 1| = x - 1\) \(|2x| - 1 = 2x - 1\) \(\because |2x - 1| = 2x -1 = x + x - 1 = |x | + |x - 1|\) given equality holds. Hence, given equality holds for \(x\in(-\infty, 0]\cup[1,\infty)\). |
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| 50. |
19. Range of the function \( f(x)=\frac{1}{\cos \left(\sin ^{-1}(\sin x+\cos x)\right\}} \) is (A) \( [-1,1]-\{0\} \) (B) \( (-\infty,-1] \cup[1, \infty) \) (C) \( (0,1] \) (D) \( (1, \infty) \)Ans.D |
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Answer» range of (sin x + cos x ) is [ -√2 ,+√2] but the domain of sin-1 x is limited to [-1,+1] so range of function sin-1 is[-π/2 ,+π/2] this means domain of func cosine will be [-π/2 ,+π/2] So range of cosine function would be [0,1] and range of F(x) will be [1 , infinity) hence D option |
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