RankLab
Back to Questions
MathsMediumAssertion Reasoning2014 · 19 Apr Online

Q73.Let x , M and σ2 be respectively the mean, mode and variance of n observations x1, x2, . ..., xn and di = −xi −a, i = 1, 2, . ..., n, where a is any number. Statement I: Variance of d1, d2, . . . , dn is σ2 . ¯Statement II: Mean and mode of d1, d2, . . . . , dn are −x −a and −M −a, respectively. (1) Statement I and Statement II are both true (2) Statement I and Statement II are both false (3) Statement I is true and Statement II is false (4) Statement I is false and Statement II is true

What This Question Tests

This question assesses the understanding of how mean, mode, and variance are affected by a change of origin (addition/subtraction of a constant) and scale (multiplication by a constant).

Concepts Tested

Properties of mean, mode, and variance under transformationsChange of origin and scale

Formulas Used

Mean(ax+b) = aMean(x)+b

Mode(ax+b) = aMode(x)+b

Variance(ax+b) = a²Variance(x)

📚 NCERT Sections This Tests

6.11Dynamics Of Rotational

Physics Class 11 · Chapter 6

69% match

6.11 Dynamics of rotational the motion of extended bodies. motion about a fixed axis A large class of problems with extended bodies can be

4.13How Is The Variability In Oxidation States Of Transition Metals Different From

Chemistry Class 11 · Chapter 4

69% match

4.13 How is the variability in oxidation states of transition metals different from that of the non transition metals? Illustrate with examples.

3.10In A Reaction Between A And B, The Initial Rate Of Reaction (R0) Was Measured

Chemistry Class 11 · Chapter 3

68% match

3.10 In a reaction between A and B, the initial rate of reaction (r0) was measured for different initial concentrations of A and B as given below: A/ mol L–1 0.20 0.20 0.40 B/ mol L–1 0.30 0.10 0.05 r0/mol L–1s–1 5.07 × 10–5 5.07 × 10–5 1.43 × 10–4 What is the order of the reaction with respect to A and B? 3.11 The following results have been obtained during the kinetic studies of the reaction: 2A + B ® C + D Experiment [A]/mol L–1 [B]/mol L–1 Initial rate of formation of D/mol L–1 min–1 I 0.1 0.1 6.0 × 10–3 II 0.3 0.2 7.2 × 10–2 III 0.3 0.4 2.88 × 10–1 IV 0.4 0.1 2.40 × 10–2 Determine the rate law and the rate constant for the reaction. 3.12 The reaction between A and B is first order with respect to A and zero order with respect to B. Fill in the blanks in the following table: Experiment [A]/ mol L–1 [B]/ mol L–1 Initial rate/ mol L–1 min–1 I 0.1 0.1 2.0 × 10–2 II – 0.2 4.0 × 10–2 III 0.4 0.4 – IV – 0.2 2.0 × 10–2 3.13 Calculate the half-life of a first order reaction from their rate constants given below: (i) 200 s–1 (ii) 2 min–1 (iii) 4 years–1 3.14 The half-life for radioactive decay of 14C is 5730 years. An archaeological artifact containing wood had only 80% of the 14C found in a living tree. Estimate the age of the sample. 3.15 The experimental data for decomposition of N2O5 [2N2O5 ® 4NO2 + O2] in gas phase at 318K are given below: t/s 0 400 800 1200 1600 2000 2400 2800 3200 102 × [N2O5]/ 1.63 1.36 1.14 0.93 0.78 0.64 0.53 0.43 0.35 mol L–1 (i) Plot [N2O5] against t. (ii) Find the half-life period for the reaction. (iii) Draw a graph between log[N2O5] and t. (iv) What is the rate law ? Chemistry 86 Reprint 2025-26 (v) Calculate the rate constant. (vi) Calculate the half-life period from k and compare it with (ii).