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. |
Let t be a real number satifying `2t ^(3) -9t ^(2) + 30 -lamda =0` where `t =x + 1/xand lamda in R.` if the cubic has exactly two real and distinct solutions for x then exhaustive set of values of `lamda` be:A. `lamda epsilon(-oo,3)uu(30,oo)`B. `lamda epsilon(-oo,-22)uu(10,oo)uu{3}`C. `lamda epsilon{3,30}`D. none of these |
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Answer» Correct Answer - B b Since domain of `f(t)=2t^(3)+30,t=x+1//x,|t|ge2f(-2)=-22f(2)=10`, critical points at `t=0` & `3,f(3)=3` |
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| 2. |
If A and B are matrices of order 3 and |A| = 5, |B|= 3 , then write the value of |3AB|. |
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Answer» |3AB|=33×|A|×|B| =27×5×3 =405 |
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| 3. |
Write the inequality for non-negative constraints of math. |
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Answer» The problem constraints are usually stated in the story problem. The linear inequalities x>=0 and y>=0. These are included because x and y are usually the number of items produced and you cannot produce a negative number of items, the smallest number of items you could produce is zero. |
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| 4. |
Write the meaning of optimal value of objective functions. |
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Answer» In an optimization problem were the objective function is to be maximized the optimal value is the least upper bound of the objective function values over the entire feasible region. If there is no upper bound, then we say that the optimal value is +∞, while if the feasible region is the empty set, we define the optimal value of a maximization problem to be −∞. Conversely, in an optimization problem were the objective function is to be minimized the optimal value is the greatest lower bound of the objective function values over the entire feasible region. If there is no lower bound, then we say that the optimal value is −∞, while if the feasible region is the empty set, we define the optimal value of a minimization problem to be +∞. Therefore, every optimization problem has a well-defined optimal value. But not every optimization problem has an optimal solution. For example, consider the optimization problem min {e x : x ∈ R}. this problem has an optimal value of zero, but there is no optimal solution. |
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| 5. |
Fastest rate of electrophilic addition will take place inA. B. C. D. |
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Answer» Correct Answer - A `+M` group stabilises the carbocation effecively therefore fast rate of electrophilic addition |
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| 6. |
At a distance r from a point located at origin in space, the electric potential varies as `V= 10r`. Find the electric field at `vecr = 3hati + 4 hatj - 5hatk`.A. `(sqrt2)(3hati+4hatj-5hatk)`B. `(-sqrt2)(3hati+4hatj-5hatk)`C. `(-sqrt3)(3hati+4hatj-5hatk)`D. none of these |
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Answer» Correct Answer - B `V=10r=10sqrt(x^(2)+y^(2)+z^(2))` `E_(x)=-(dv)/(dx)=-(10(2x))/(2sqrt(x^(2)+y^(2)+z^(2)))` `=(-10x)/(sqrt(x^(2)+y^(2)+z^(2)))=(10xx3)/(sqrt(3^(2)+4^(2)+5^(2)))=-3sqrt(2)` similarly `E_(y)=-4sqrt(2)` `E_(x)=5sqrt(2),ver(E)=E_(x)hat(i)+E_(y)hat(j)+E_(z)hat(k)` |
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| 7. |
Four charges are placed at four corners of a square as shown in figure. The side of the square is a. Two charges are positive and two are negative, but their magnitudes are the same. Now, an external agent starts decreasing all the sides of the square slowly and at the same rate. What happens to the electrical potential energy of the system and what will be the nature of work done by the agent? A. increases, positiveB. increases, negativeC. decreases, negativeD. decreases, positive |
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Answer» Correct Answer - C Electrical potential energy of system `U=-2[(kq^(2))/(sqrt(2)a)]=(-sqrt(2)kq^(2))/(a)` (four pairs will cancel each other) If `a` decreases `U` also decreases and if `U` decreases, the agent will do negative work |
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| 8. |
In which of the following pairs, electron gain enthalpies of constituent elements are nearly the same or identical ? (A) Rb and Cs (B) Na and K (C) Ar and Kr (D) I and At Choose the correct answer from the options given below : (A) (A) and (B) only (B) (B) and (C) only (C) (A) and (C) only (D) (C) and (D) only |
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Answer» (C) (A) and (C) only Rb & Cs have nearly same electron gain enthalpy electron gain enthalpy = – 46 kj/ml Ar & Kr have same ΔHeq . Value is + 96 kj/ml |
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| 9. |
A positively charged particle P enters the region between two parallel plates with a velocity u, in a direction parallel to the plates. There is a uniform electric field in this region. P emerges from this region with a velocity v. Taking C as a constant, v will depend on u as A. `v = Cu`B. `v = (sqrt(u^2+Cu))`C. `v = (sqrt(u^2+C/u))`D. `v = (sqrt(u^2 + C/u^2))` |
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Answer» Correct Answer - D `l` is the length of the each tube `u_(x)=u` constant. Time of travel between the plates is `t=l//u` let `a` be constant acceleration in y-direction so `v_(y)=at` when the particle emerges from the plates so `v^(2)=u_(x)^(2)+v_(y)^(2)=u^(2)+a^(2)t^(2)` `=u^(2)+a^(2)(l^(2))/(u^(2))=u^(2)+(C)/(u^(2))` (where `a^(2)l^(2)=C`) So, `v=sqrt(u^(2)+(C)/(u^(2)))` |
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| 10. |
Prove that the vectors(i - 2j + 5k) and vector(-2i + 4j + 2k) are mutually perpendicular. |
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Answer» Let vector a = vector(i - 2j + 5k) and vector b = vector(-2i + 4j + 2k) ∴ vector(a.b) = vector(i - 2j + 5k), vector(-2i + 4j + 2k) = -2 - 8 + 10 = 0 Hence the given vectors be perpendicular to each other |
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| 11. |
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R)Assertion (A): Boron is unable to form \(BF_6^{3+}\)Reason (R): Size of B is very small.In the light of the above statements, choose the correct answer from the options given below:(A) Both (A) and (R) are true and (R) is the correct explanation of (A)(B) Both (A) and (R) are true but (R) is not the correct explanation of (A)(C) (A) is true but (R) is false(D) (A) is false but (R) is true |
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Answer» Correct option is (B) Both (A) and (R) are true but (R) is not the correct explanation of (A) Assertion (A): True Reason (R): True but not correct explanation. Correct explanation: Expansion of octet not possible for ‘B’. ans is. b. since boron can't exhibit+6 O.S. even in the excited state so BF6 can't exist. also the size of B is small as size decrease along period. but this fact has nothing to do with formation of BF6. hence not correct explanation |
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| 12. |
Identify the incorrect statement from the following. (A) A circular path around the nucleus in which an electron moves is proposed as Bohr’s orbit. (B) An orbital is the one electron wave function (ψ) in an atom. (C) The existence of Bohr’s orbits is supported by hydrogen spectrum. (D) Atomic orbital is characterised by the quantum numbers n and l only |
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Answer» (D) Atomic orbital is characterised by the quantum numbers n and l only Atomic orbital is characterised by n, l, m. |
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| 13. |
If the 4th term of the binomial expansion [2/x + x^log8x]6 ,(x>0) is 20*87 then x=? |
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Answer» Refers to the below link https://wow.link/b35
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| 14. |
If x = a cos θ, y = b sin θ, find dy/dx. |
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Answer» ∵ x = a cos θ, y = b sin θ ∴ dx/dθ = -a sin θ = dy/dθ = b cos θ ∴ dy/dx = b cos θ/-a sin θ = - (b/a) cot θ |
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| 15. |
If y = √(x2 + ax + 1), then find dy/dx. |
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Answer» ∵ y = √(x2 + ax + 1) ∴ dy/dx = 1/2√(x2 + ax + 1)(2x + a) = ((2x + a)/2√(x2 + ax + 1) |
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| 16. |
In the set Q of all rational numbers, a binary operation o : Q x Q → Q, is defined by o(x, y) = x o y = x + y - xy, then show that o is commutative. |
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Answer» Let x,y ∈ Q then xoy = x + y - xy = y + x - yx = yox hence o commutative |
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| 17. |
The area of guardriateral formed by the lines y = 2x + 3, y = 0, x = 4, x = 6 is equal to which of the following ?(A) 26 square unit (B) 24 square unit (C) 20 square unit (D) None of these |
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Answer» (A) 26 square unit |
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| 18. |
Reactions involving stereoisomers To study the involvement of stereoisomers in chemical reactions we shall take up following points: (i)The conversion of an achiral molecule into a chiral molecule, with the generations of a chiral centre. Secondary butyl chloride exist as two enantiomers but mixture is optically inactive due to formation of a racemic mixture.Both enantiomers are obtained in equal amounts.Racemic mixture is an eqnimolar mixture of two enantiomers. (ii)Conversion of chiral molecule into chiral and achiral molecules. Monochlorination of which of the following will give only an achiral products ?A. n-PentaneB. IsopentaneC. NeopentaneD. All of these |
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Answer» Correct Answer - C neopentane `overset(Cl_2//hv)to CH_3-undersetunderset(CH_3)(|)oversetoverset(CH_3)(|)C-CH_2Cl`(Achiral product) |
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| 19. |
Let f = {(1, 1), (2, 3), (0, –1), (–1, –3)} be a function from Z to Z defined by f(x) = ax + b, for some integers a, b. Determine a, b. |
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Answer» f = {(1, 1), (2, 3), (0, –1), (–1, –3)} and f(x) = ax + b (1, 1) ∈ f ⇒ f(1) = 1 ⇒ a × 1 + b = 1 ⇒ a + b = 1 (0, –1) ∈ f ⇒ f(0) = –1 ⇒ a × 0 + b = –1 ⇒ b = –1 On substituting b = –1 in a + b = 1, We obtain a + (–1) = 1 ⇒ a = 1 + 1 = 2. Thus, the respective values of a and b are 2 and –1. |
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| 20. |
Let R be a relation from N to N defined by R = {(a, b): a, b ∈ N and a = b2}. Are the following true? (i) (a, a) ∈ R, for all a ∈ N (ii) (a, b) ∈ R, implies (b, a) ∈ R (iii) (a, b) ∈ R, (b, c) ∈ R implies (a, c) ∈ R. Justify your answer in each case. |
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Answer» R = {(a, b): a, b ∈ N and a = b2} (i) It can be seen that 2 ∈ N; however, 2 ≠ 22 = 4. Therefore, the statement “(a, a) ∈ R, for all a ∈ N” is not true. (ii) It can be seen that (9, 3) ∈ N because 9, 3 ∈ N and 9 = 32. Now, 3 ≠ 92 = 81; therefore, (3, 9) ∉ N Therefore, the statement “(a, b) ∈ R, implies (b, a) ∈ R” is not true. (iii) It can be seen that (9, 3) ∈ R, (16, 4) ∈ R because 9, 3, 16, 4 ∈ N and 9 = 32 and 16 = 42. Now, 9 ≠ 42 = 16; therefore, (9, 4) ∉ N Therefore, the statement “(a, b) ∈ R, (b, c) ∈ R implies (a, c) ∈ R” is not true. |
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| 21. |
The solubility product `(K_(sp))` of sparingly soluble salt `AgIO_(3)` is `1xx10^(-8)` at a given temperature. What is the mass of `AgIO_(3)` (molar mass `=283`) contained in `100ml` solution at this temperature `:-`A. `1xx10^(-4)g`B. `28.3xx10^(-2)g`C. `2.83xx10^(-3)g`D. `1xx10^(-7)g` |
| Answer» Correct Answer - C | |
| 22. |
Let f be the subset of Z × Z defined by f = {(ab, a + b): a, b ∈ Z}. Is f a function from Z to Z: justify your answer. |
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Answer» The relation f is defined as f = {(ab, a + b): a, b ∈ Z} We know that a relation f from a set A to a set B is said to be a function if every element of set A has unique images in set B. Since 2, 6, –2, –6 ∈ Z, (2 × 6, 2 + 6), (–2 × –6, –2 + (–6)) ∈ f i.e., (12, 8), (12, –8) ∈ f It can be seen that the same first element i.e., 12 corresponds to two different images i.e., 8 and –8. Thus, relation f is not a function. |
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| 23. |
Reactions involving stereoisomers To study the involvement of stereoisomers in chemical reactions we shall take up following points: (i)The conversion of an achiral molecule into a chiral molecule, with the generations of a chiral centre. Secondary butyl chloride exist as two enantiomers but mixture is optically inactive due to formation of a racemic mixture.Both enantiomers are obtained in equal amounts.Racemic mixture is an eqnimolar mixture of two enantiomers. (ii)Conversion of chiral molecule into chiral and achiral molecules. Which of the following reactant will give chiral products on monochlorination ?A. `CH_3-CH_2-CH_3`B. `CH_3-undersetunderset(CH_3)(|)CH-CH_3`D. |
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Answer» Correct Answer - D `CH_3-undersetunderset(CH_3)(|)CH-undersetunderset(CH_3)(|)CH-CH_3 overset(Cl_2//hv)toCH_3-undersetunderset(CH_3)(|)CH-undersetunderset(CH_3)(|)CH-CH_2Cl` (Chiral product) |
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| 24. |
The solubility of a sparingly soluble salt `A_xB_y` in water at `25^@C=1.5xx10^(-4)M`.The solubility product is `1.1xx10^(-11)` The possibilities areA. x=1 ,y=2B. x=2,y=1C. x=1,y=3D. x=3,y=1 |
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Answer» Correct Answer - A,B `K_(sp)=1.1xx10^(-11)=(1.4 xx 10^(-4))^(x+y)x^x. y^y` so we have x+y=3 (by comparing values ) so, `x^x .y^y=(1.1xx10^(-11))/(1.4xx1.4xx1.4xx10^(-12))=110/(1.6xx1.4)=4` Hence x=1, y=2 y=1, x=2 |
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| 25. |
Compare the acidity of four hydrogen atoms x, y, z and w ? A. x is more acidic than zB. y is more acidic than xC. z is more acidic than wD. x is most acidic and w is least acidic amongst the four hydrogen atoms |
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Answer» Correct Answer - A,C,D The acidity order is xgtzgtygtw |
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| 26. |
Which of the following property of alkali metals/alkali metal salt increase with increase in atomic number ?A. Solubility of their hydroxidesB. Thermal stability of their carbonatesC. Their softnessD. Their hydration energies |
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Answer» Correct Answer - A,B,C Hydration energy `prop ("Charge on cation")/("Size of cation")`, (A) (B) and (C ) are correct statements. |
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| 27. |
In the parallelogram ABCD A(2, 3); B(7, 3); and D(4, 7). Find the coordinates of C. |
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Answer» In the figure ΔAED, ΔBFC AD = BC. DE = CF AE = BF = 2 unit ∴ x coordinate of C = 7 + BF = 7 + AE = 7 + 2 = 9 y coordinate of C = 3 + FC = 3 + ED = 3 + 4 = 7 C has the coordinates (9, 7) |
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| 28. |
Write the coordinates of each points on the lines 2x – y + 1 = 0 and 3x – 2y + 3 = 0. Find the co-ordinates of the point of intersection of the lines. |
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Answer» The line 2x - y + 1 = 0 x = 2 then 4 - y + 1 = 0 y = 5; (2,5) The line 3x - 2y + 3 = 0 x = 3 then 9 - 2y + 3 = 0 2y = 12; y = 6; (3, 6) 4x - 2y + 2 = 0 3x + 2y + 3 = 0 (1) + (2), x - 1 = 0 x = 1 x = 1 (put value in (1)) 4x 1 - 2y + 2 = 0 y = 3 intersecting points = (1, 3) |
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| 29. |
Express 3.28 in the simplest form Of p/q |
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Answer» 3.28 = 328/100 = 164/50 = 82/25 Ans |
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| 30. |
What is an integer? |
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Answer» An integer is a whole number (not a fractional number) that can be positive, negative, or zero. Examples of integers are: -5, 1, 5, 8, 97, and 3,043. Examples of numbers that are not integers are: -1.43, 1 3/4, 3.14, . 09, and 5,643.1. |
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| 31. |
Suppose P and Q are two different matrices of order `3xx n " and" n xx p`, then the order of the matrix `P xx Q` is ?A. `3 xx p`B. `p xx 3`C. `n xx n`D. `3 xx 3` |
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Answer» Correct Answer - A `3xxp` |
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| 32. |
Solve the equation 2x2 - 5x + 3 by the method of completing the square method. |
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Answer» 2x2 - 5x + 3 = 0 2x2/2 - 5x/2 + 3/2 = 0 (dividing both sides by 2) x2 - 5x/2 + 3/2 = 0 [x2 - 5x/2 + (5/4)2] - (5/4)2 + 3/2 = 0 [x - 5/4]2 - 25/16 + 3/2 = 0 [x - 5/4]2 - (25-24)/16 = 0 [x - 5/4]2 - 1/16 = 0 [x - 5/4]2 = 1/16 x - 5/4 = ± 1/4 (square rooting on both sides) x = 1/4 + 5/4 or x = -1/4 + 5/4 x = (1+5)/4 or x = (-1+5)/4 x = 6/4 or x = 4/4 x = 3/2 or x = 1 |
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| 33. |
The following real numbers have decimal expansions as given below. In each case, decide whether they are rational or not. If they are rational, and of the form p/q, what can you say about the prime factors of q? i. 43.123456789 ii. 0.120120012000120000… iii. 43.123456789 |
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Answer» Solution: ii. Since the decimal expansion is neither terminating nor recurring, the given number is an irrational number. |
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| 34. |
π-22/7 is (A) a rational number (B) an irrational number (C) a prime number (D) an even number |
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Answer» It is (B) an irrational number |
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| 35. |
The product of a non zero rational and an irrational number is(A) always irrational(B) always rational(C) rational or irrational(D) one |
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Answer» The product of a non zero rational and an irrational number is always irrational |
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| 36. |
The product of two irrational numbers is(A) always a rational(B) always an irrational(C) one(D) always a non-zero number |
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Answer» Correct answer is (D) always a non-zero number |
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| 37. |
If A is any square matrix of order `3xx3` such that |A|=3, then the value of |adjA| is ?A. 3B. `(1)/(3)`C. 9D. 27 |
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Answer» Correct Answer - C 9 |
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| 38. |
The unit vector in the direction of the vector \(\vec i-3\vec j +5\vec k\) is :(A) \(\frac{\vec i-3\vec j +5\vec k}{\sqrt{35}}\) (B) \(\frac{\vec i-3\vec j +5\vec k}{\sqrt{28}}\) (C) \(\frac{\vec i-3\vec j +5\vec k}{\sqrt{29}}\) (D) None of thesei - 3j + 5k |
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Answer» Option : (A) \(\frac{\vec i-3\vec j +5\vec k}{\sqrt{35}}\) |
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| 39. |
State and prove the Pythagoras theorem. |
| Answer» For correct statement, Given, To prove, Construction and Figure For correct proof | |
| 40. |
If \(\vec a=-\vec i-2\vec j-4\vec k\) and \(\vec b=-2\vec i-3\vec j\) then the value of \(|\vec a + \vec b|\) is :(A) 2√2 (B) 3√2 (C) 4√2(D) 5√2a = -i - 2j - 4k b = -2i - 3j|a + b| |
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Answer» Option : (D) 5√2 |
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| 41. |
The distance of the plane 3x + 4y + 5z = 6 from origin is :(A) \(\frac{6}{5\sqrt 2}\) (B) \(\frac{6}{7\sqrt 2}\) (C) 11(D) None of these |
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Answer» Option : (A) \(\frac{6}{5\sqrt 2}\) |
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| 42. |
The angle between the planes 2x + y + z = 11 and x – 2y + z = 5 is :(A) cos-1\(\frac{1}{6}\) (B) cos-1\(\frac{1}{3}\) (C) \(\frac{\pi}{4}\) (D) None of these |
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Answer» Option : (A) cos-1\(\frac{1}{6}\) |
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| 43. |
\(\int_1^\sqrt 3\frac{dx}{1+x^2}\) =(A) \(\frac{\pi}{3}\)(B) \(\frac{2\pi}{3}\)(C) \(\frac{\pi}{6}\)(D) \(\frac{\pi}{12}\)∫ dx/(1+x2), x ∈ (1,√3) = |
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Answer» Option : (D) \(\frac{\pi}{12}\) |
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| 44. |
\(|2\vec j-2\vec k-\vec i|=\) (A) 3 (B) 4 (C) 5 (D) 1|2j - 2k - i| = |
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Answer» Option : (A) 3 |
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| 45. |
The direction cosines of the line having direction ratios 1, 2, 3 are :(A) \(\frac{1}{\sqrt 7}\),\(\frac{2}{\sqrt 7}\),\(\frac{3}{\sqrt 7}\) (B) \(\frac{1}{\sqrt {11}}\),\(\frac{2}{\sqrt {11}}\),\(\frac{3}{\sqrt {11}}\) (C) \(\frac{1}{\sqrt {14}}\),\(\frac{2}{\sqrt {14}}\),\(\frac{3}{\sqrt {14}}\) (D) None of these |
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Answer» Option : (C) \(\frac{1}{\sqrt {14}}\),\(\frac{2}{\sqrt {14}}\),\(\frac{3}{\sqrt {14}}\) |
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| 46. |
\((3\vec i - 4\vec j).(2\vec i-3\vec j + 4\vec k)=\)(A) 22 (B) 16 (C) 18 (D) 25(3i - 4j).(2i - 3j + 4k) = |
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Answer» Option : (C) 18 |
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| 47. |
Evaluate : (i - j - k) . (2i + 2j - k)\((\vec i-\vec j-\vec k).(2\vec i+\vec j -\vec k)=\)(A) 0 (B) -3 (C) 1 (D) -1 |
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Answer» Option : (C) 1 |
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| 48. |
\((7\vec i - 3\vec j+5\vec k) .(2\vec i + 3\vec j- 5\vec k)=\) (A) 0 (B) 1 (C) 2 (D) 28(7i - 3j + k) . (2i + 3j - 5k) = |
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Answer» Option : (A) 0 |
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| 49. |
Evaluate : ∫xe5xdx (A) \(\frac{6^{5x}}{25}\)(5x - 1) + K(B) \(\frac{6^{5x}}{25}\)(5x + 1) + K(C) e5x(5x + 1) + K(D) 5xe5x + K |
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Answer» Option : (A) \(\frac{6^{5x}}{25}\)(5x - 1) + K |
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| 50. |
\(4\vec i.(7\vec i-8\vec j+3\vec k)=\)(A) 4 (B) 28 (C) -32 (D) 124i.(7i - 8j + 3k) = |
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Answer» Option : (B) 28 \(4\hat{i}.(7\hat{i} - 8\hat{j} + 3\hat{k})\) \(= 28\,\hat{i}.\hat{i} - 32\,\hat{i}.\hat{j} + 12\,\hat{i}.\hat{k}\) \(= 28(\because \hat{i}.\hat{i} = 1\,\, \&\,\, \hat{i}.\hat{j} = \,\hat{i}.\hat{k} = 0)\) Option : (B) 28 |
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