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A circular hole of radius (a/2) is cut out of a circular disc of radius ‘a’ shown in figure. The centroid of the remaining circular portion with respect to point ‘O’ will be:

A circular hole of radius (a/2) is cut out of a circular disc of radius ‘a’ shown in figure. The centroid of the remaining circular... View Article

On the basis of kinetic theory of gases, the gas exerts pressure because its molecules:

a. suffer change in momentum when impinge on the walls of container. b. continuously stick to the walls of container. c. continuously lose... View Article

An X-ray tube is operated at 1.24 million volt. The shortest wavelength of the produced photon will be:

a. 10-2 nm b. 10-3 nm c. 10-4 nm d. 10-1 nm Answer: (b) The minimum wavelength of photon will correspond to the maximum energy due to... View Article

According to Bohr atom model, in which of the following transitions will the frequency be maximum?

a. n = 2 to n = 1 b. n = 4 to n = 3 c. n = 5 to n = 4 d. n = 3 to n = 2 Answer: (a) Since, ΔE is maximum for the transition from n = 2 to... View Article

Zener breakdown occurs in a p-n junction having p and n both:

a. lightly doped and have wide depletion layer. b. heavily doped and have narrow depletion layer. c. heavily doped and have wide depletion layer.... View Article

Dichromate ion is treated with base, the oxidation number of Cr in the product formed is:

Answer: 6 Cr2O72- + 2OH- ⇌ 2CrO42- + H2O For CrO42- x + (–2 × 4) = –2 x = 6... View Article

A homogeneous ideal gaseous reaction AB_2(g) ⇌ A_(g) + 2B_(g) is carried out in a 25 liter flask at 27^oC. The initial amount of AB₂ was 1 mole and the equilibrium pressure was 1.9 atm. The value of K_p is x × 10^–2. The value of x is ______. [R = 0.08206 dm³ atm K^–1 mol^–1]

Answer: 74 The answer is 74... View Article

A certain gas obeys P(V_m – b) = RT. The value of (∂Z/∂P)_T is xb/RT. The value of x is ______.
Answer: 1 P(v – b) = RT PV – Pb = RT Z = 1 + PV/RT dZ/dP = 0 + b/RT b/RT = xb/RT x = 1... View Article

For a chemical reaction A +B ⇌ C + D (Δ_rH^ψ = 80 kJ mol^–1) the entropy change Δ_rS^ψ depends on the temperature T (in K) as Δ_rS^ψ = 2T (J K^–1 mol^–1). Minimum temperature at which it will become spontaneous is ________K.

For a chemical reaction A +B ⇌ C + D (ΔrHψ = 80 kJ mol–1) the entropy change ΔrSψ depends on the temperature T (in... View Article

Number of bridging CO ligands in [Mn₂(CO)₁₀] is _____.
Number of bridging CO ligands in [Mn2(CO)10] is _____. Answer: 0 Fact Hence the answer is 0... View Article

The number of significant figures in 50000.020 × 10^–3 is _______.
Answer: 7 50000.020 × 10–3 Number of significant figures = 7... View Article

3.12 g of oxygen is adsorbed on 1.2 g of platinum metal. The value of oxygen adsorbed per gram of the adsorbent at 1 atm and 300 K in L is _______.
[R = 0.0821 L atm K–1 mol–1] Answer: 2 Moles of O2 = 3.12/32 = 0.0975 volume of O2 = nRT/P = (0.0975 ×0.082×300)/1 volume... View Article

Consider the following reaction
Consider the following reaction MnO4- + 8H+ + 5e– → Mn+2 + 4H2O, Eo = 1.51 V. The quantity of electricity required in Faraday to... View Article

224 mL of SO_2(g) at 298 K and 1 atm is passed through 100 mL of 0.1 M NaOH solution. The non-volatile solute produced is dissolved in 36 g of water. The lowering of vapour pressure of solution (assuming the solution is dilute) (P(H₂O)= 24 mm of Hg) is 10^–2 x mm of Hg, the value of x is _____

Answer: 0.18 The balanced equation is SO2 + 2NaOH → Na2SO3 + H2O moles of NaOH = molarity × volume (in litre) = 0.1 × 0.1 = 0.01... View Article

The structure of Neoprene is:
The structure of Neoprene is: Answer: (b) ... View Article

Identify the major products A and B respectively in the following reaction of phenol:
Identify the major products A and B respectively in the following reaction of phenol: Answer: (a) Hence the answer is a... View Article

Which one of the following lanthanoids does not form MO2? [M is lanthanoid metal]
[M is lanthanoid metal] a. Nd b. Yb c. Dy d. Pr Answer: (b) Fact... View Article

16 June 2021: UPSC Exam Comprehensive News Analysis
CNA 16th June 2021:- Download PDF Here TABLE OF CONTENTS A. GS 1 Related B. GS 2 Related POLITY AND GOVERNANCE 1. Delhi riots: 3 student... View Article

Hague Convention on Child Abduction
International conventions and treaties are important under several topics in the UPSC syllabus. They feature in the news many times and to... View Article

15 June 2021: PIB Summary & Analysis
June 15th, 2021, PIB:- Download PDF Here TABLE OF CONTENTS 1. Mandatory Hallmarking of Gold Jewellery 2. Global Yoga Conference 2021 3. Code on... View Article

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