All questions
- If vector a,b,c are three mutually perpendicular vectors equally inclined to vector a + b + c at angle θ, then find the value of 36 cos^2 2θ. Answer: 4 Let vec s = vec a + vec b + vec c . Since the vectors are mutually perpendicular, vec a·vec b = vec b·vec c = vec c·vec a = 0 , so... 1
- The mean of 6 numbers is 6.5 and its variance is 10.25. If 4 numbers are 2,4,5 and 7, then find the other two. Answer: the other two numbers are 10 and 11 Let the other two numbers be a and b . Mean: sum of all six = 6×6.5 = 39 . The given four add to... 1
- The initial velocity vi required to project a body vertically upward from the surface of the earth to reach a height of 10R, where R is the radius of the earth, Correct answer is 10 1
- The radius in kilometer to which the present radius of earth (R = 6400 km) Correct answer is 64 km Explanation:: 1
- which of the following is most easily economically refined by fractional distillation Correct option is A) Zn 2
- If P4O10 + HNO3 are mixed in 1:4 ratio , then nature of nitrogen oxide obtained will be 4HNO₃ +P₄ O₁₀ →2N₂ O ₅+4HPO_(3 ) and N₂O₅ is acidic in nature 1
- What is disproportionate ? in chemistry A disproportionation reaction is one in which a species has been both oxidised and reduced (that is, the oxidation state of the related spec... 1
- Benzene has vapor pressure of 70 torr and methyl benzene has 20 torr . Answer: y_benzene = 7/9 ≈ 0.78 For an equimolar ideal solution, x_benzene = x_toluene = 0.5 . By Raoult's law, the partial pressures are p_B... 1
- In △ABC , cos B= 3/5 , AB=5 and R=5 . find the area of △ABC correct answer is 6+8√3 2
- find the coefficient of x^256 in [1-x]^101 x (x^2+x+1)^100 Correct answer is ¹⁰⁰C₈₅ or ¹⁰⁰C₁₅ 1
- tangent and normal are drawn to y^2=2x at A(2,2). tangent cuts x-axix at T and normal cuts parabola again at P Ans is : 25/2 {area of ▵ ATP } 2
- Bird is flying in northeast direction with v 4rt^2 wind from north to south with 1m/s find the Ans: 15 m {displacement of bird} 2
- 6.02 × 1020 molecules of urea are present in 100 ml of its solution. Jee Answer: B) 0.01 M Moles of urea: n = frac6.02×10²⁰6.02×10²³ = 1×10⁻³\ mol Volume of solution = 100\ mL = 0.1\ L . Molarity = frac10⁻³\ mol0.... 1
- Number of atoms in 558.5 gram Fe (at. wt. of Fe = 55.85 g mol-1) is Answer: (a) twice that in 60 g carbon Moles of Fe = 558.5/55.85 = 10 mol, so the number of atoms is 10N_A = 6.023×10²⁴ . Check each option:... 1
- In a compound C, H and N atoms are present in 9 : 1 : 3.5 by weight . Answer: C₆H₈N₂ Divide each mass by the atomic mass to get the mole ratio: C: 9/12 = 0.75 H: 1/1 = 1 N: 3.5/14 = 0.25 Dividing by the smalles... 1
- With increase of temperature, which of these changes? JEE Option C is correct molarity Temperature has no effect on mass but it has significant effect on volumes. Hence molality, mole fraction, mass... 1
- If both FeX2 & FeY3 are found to exist, X & Y can be : (1) X = F, Cl, Br, I Y = F, Cl, Br (2) X = Cl, Br, (1) X = F, Cl, Br, I :: Y = F, Cl, Br is the correct option Explaination:: FeI₃ does not exist as I^(–) reduces Fe³⁺ to Fe²⁺. 2Fe³⁺ + 2I – →... 1
- The period of oscillation of a simple pendulum is T = 2π\sqrt{Lg}. Measured value of 'L' is 1.0 m from meter Answer: (1) 1.13% Step 1: Write g in terms of the measured quantities. T = 2π√(L/g) ⇒ g = frac4π²LT² Step 2: Relative error. For a product o... 1
- WAP in C++ that first initializes an array of given 10- sorted real numbers. The program must verify whether a given Output:: Below code is executed on gdb turbo c++ compiler , it takes 10 input of given number then sort by binary search technique #include<... 2
- write html code for following Faculty Arts Science Commerce Code :: <!DOCTYPE html> <table border="1" cellspacing="10px"> <tr> <th rowspan="2" colspan="2" > </th> <th colspan="3"> Faculty</th> </tr> <... 1
- JEE MAINS EXAM APRIL AND MAY SESSION DATES JEE MAINS EXAM APRIL AND MAY SESSION DATES https://jeemain.nta.nic.in/webinfo2021/Page/Page?PageId=1&LangId=P May attempt is postponed 1
- The least value of |z| where z is complex number which satisfies the inequality Answer: (1) 3 Read the inequality as exp((|z|+3)(|z|-1)/|z|+1log_e 2) ≥ log_(sqrt2)|5sqrt7 + 9i| . Right side: |5sqrt7 + 9i| = √(175 + 81) =... 1
- The area of the triangle with vertices A(z), B(iz) and C (z + iz) is : Answer: (2) 1/2|z|² Look at the sides meeting at C: overrightarrowCA = z - (z + iz) = -iz , length |z| . overrightarrowCB = iz - (z + iz) =... 1
- Let S1, S2 and S3 be three sets defined as S1 = {z ∈ C : |z - 1| ≤ √2} Answer: (3) Has infinitely many elements Let z = x + iy . S₁ : |z-1| ≤ sqrt2 is the closed disc with centre (1, 0) and radius sqrt2 . S₂ : (... 1