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MathsMediumMCQ2020 ยท 03 Sep Shift 2

Q64.If the surface area of a cube is increasing at a rate of 3. 6cm2/sec, retaining its shape; then the rate of change of its volume (in cm3/sec), when the length of a side of the cube is 10cm, is: (1) 20 (2) 10 (3) 18 (4) 9 = A(x) tanโˆ’1(โˆšx) + B(x) + C , where C is a constant of integration, then the

What This Question Tests

This question tests the ability to apply the concept of related rates using differentiation. It requires setting up equations for surface area and volume of a cube and differentiating them with respect to time.

Concepts Tested

DifferentiationChain RuleGeometric Formulas

Formulas Used

A = 6s^2

V = s^3

dA/dt = 12s(ds/dt)

dV/dt = 3s^2(ds/dt)

๐Ÿ“š NCERT Sections This Tests

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

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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 Lโ€“1 0.20 0.20 0.40 B/ mol Lโ€“1 0.30 0.10 0.05 r0/mol Lโ€“1sโ€“1 5.07 ร— 10โ€“5 5.07 ร— 10โ€“5 1.43 ร— 10โ€“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 ยฎ C + D Experiment [A]/mol Lโ€“1 [B]/mol Lโ€“1 Initial rate of formation of D/mol Lโ€“1 minโ€“1 I 0.1 0.1 6.0 ร— 10โ€“3 II 0.3 0.2 7.2 ร— 10โ€“2 III 0.3 0.4 2.88 ร— 10โ€“1 IV 0.4 0.1 2.40 ร— 10โ€“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 Lโ€“1 [B]/ mol Lโ€“1 Initial rate/ mol Lโ€“1 minโ€“1 I 0.1 0.1 2.0 ร— 10โ€“2 II โ€“ 0.2 4.0 ร— 10โ€“2 III 0.4 0.4 โ€“ IV โ€“ 0.2 2.0 ร— 10โ€“2 3.13 Calculate the half-life of a first order reaction from their rate constants given below: (i) 200 sโ€“1 (ii) 2 minโ€“1 (iii) 4 yearsโ€“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 ยฎ 4NO2 + O2] in gas phase at 318K are given below: t/s 0 400 800 1200 1600 2000 2400 2800 3200 102 ร— [N2O5]/ 1.63 1.36 1.14 0.93 0.78 0.64 0.53 0.43 0.35 mol Lโ€“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).

1.18 โ€” A Point Charge Of 2.0 Mc Is At The Centre Of A Cubic Gaussian

Physics Class 11 ยท Chapter 1

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1.18 A point charge of 2.0 mC is at the centre of a cubic Gaussian surface 9.0 cm on edge. What is the net electric flux through the surface?

3.9 โ€” A Reaction Is First Order In A And Second Order In B.

Chemistry Class 11 ยท Chapter 3

71% match

3.9 A reaction is first order in A and second order in B. (i) Write the differential rate equation. (ii) How is the rate affected on increasing the concentration of B three times? (iii) How is the rate affected when the concentrations of both A and B are doubled? 85 Chemical Kinetics Reprint 2025-26