Archives

The reaction of cyanamide NH2CN(s) with dioxygen was carried out in a bomb calorimeter and △U was found to be – 742.7 kJ mol^-1 at 298 K. Calculate enthalpy change for the reaction at 298 K NH2CN(g) + 3/2 O2(g) →N2(g) + CO2(g) + H2O(I)

Given △U = -742.7 kJ mol-1 △ng = np - nr = 2 - 3/2 = 1/2 = 0.5 mol R = 8.314 x 10-3 kJ mol-1 We know, △H = △U + △ngRT On substituting the... View Article

What is the principal function of the eyelens?

The principal function of the eye lens is to focus the light from an object entering the eye and produce a real and inverted image of the object... View Article

CH3 – CH2 – CH2 – CHO IUPAC name of the compound is:

Given CH3-CH2-CH2-CHO The IUPAC name of the compound CH3-CH2-CH2-CHO is Butanal... View Article

Consider the reaction Cr2O7^2− +14H^+ + 6e^− →2Cr^3+ + 7H2O. What is the quantity of electricity in coulombs needed to reduce 1 mol of Cr2O7^2-? (A) 6 x 10^6 C (B) 5.79 x 10^5 C (C) 5.25 x 10^5 C (D) None of these

Given reaction is 1 F = 96500 C = 1 mole of e- 1 mole of → 6 moles of e- 1 mole of e- = 96500 C 6 moles of e- = 6 x 96500 C We... View Article

The displacement x of a particle at time t along a straight line is given by x = α – βt + γt^2. Find the acceleration of the particle.

Given Displacement x = α - βt + γt2 ......... (1) where α, β and γ are constants Differentiating equation (1)... View Article

A motorcyclist wants to drive on the vertical surface of a wooden wall of radius 5m, with a minimum speed of 5√5. The minimum value of coefficient of friction between the tyres and the wall of the wood must be: (Take g = 10 ms^-2) (A) 0.10 (B) 0.20 (C) 0.30 (D) 0.40

Given A motorcyclist wants to drive on the vertical surface of a wooden wall of radius 5m, with a minimum speed of 5√5 To find the... View Article

A farmer runs a pipe of internal diameter 20 cm from the canal into a cylindrical tank in his field which is 10 m in diameter and 2 m deep. If water flows through the pipe at the rate of 3 km/h, in how much time will the tank be filled?

Given Internal radius of the pipe = 10 cm = 0.1m Water flowing in the pipe at 3km/hr = 3000m/hr Let the cylindrical tank will be filled in t... View Article

Hydrogen atom in ground state is excited by a monochromatic radiation of λ = 975 Å. Number of spectral lines in the resulting spectrum emitted will be (A) 3 (B) 2 (C) 6 (D) 10

Energy of the photon, E = hc/λ E = (6.63 x 10-34 x 3 x 108)/(975 x 10-10)J E = (6.63 x 10-34 x 3 x 108)/(975 x 10-10 x 1.6 x 10-19) eV We... View Article

Find the next term of the series, 1728, 2744, 4096, 5832, 8000, 10648,? (A) 2167 (B) 13824 (C) 15625 (D) 9261 (E) 17576

Given terms of series are 1728, 2744, 4096, 5832, 8000, 10648,... 123 = 1728 143 = 2744 163 = 4096 183 = 5832 203 = 8000 223 = 10648 243 =... View Article

Three 2 omega resistors, A, B and C are connected as shown in figure. Each of them dissipates energy and can withstand a maximum power of 18 W without melting. Find the maximum current that can flow through the three resistors?

Current P = I2R 18W = I2 x 2Ω I2 = 18W/2Ω We get, I2 = 9 I = 3A Therefore, the maximum current that can flow through the... View Article

Bad debt amount should be credited to the ___________ account (A) Debtors (B) Bad debts (C) Sales (D) Creditors

Debtors Bad debts refer to the amount that the firm has not been able to realise from its debtors. It is regarded as a loss and is termed as bad... View Article

For a freely falling body the initial velocity is given by (A) v = v^2 + 2gh (B) v = gt^2 (C) v = 0 (D) None of these

v = 0 When an object falls from a certain height which is under the influence of gravitational force, it is known as the free fall. The speed... View Article

The quantity of electricity required to liberate 112 cc hydrogen at STP from acidified water is ___________ (A) 965 C (B) 9650 C (C) 96500 C (D) 4825 C

2H+ + 2e- → H2 2F is required to liberate 22.4 L of H2 gas 1000 cc = 1L 112 cc = 0.112 L For 22.4 L we require 193000 C of charge [Since... View Article

Fear or excitement generally cause on to breathe rapidly and it results in the decrease of CO2 concentration in blood. In what way will it change the pH of blood? (A) pH will increase (B) pH will decrease (C) No change (D) pH will be 7

No change Since blood is a buffer solution so its pH will remain constant and doesn't change with concentration of CO2. It contains a serum... View Article

Archives

The reaction of cyanamide NH2CN(s) with dioxygen was carried out in a bomb calorimeter and △U was found to be – 742.7 kJ mol^-1 at 298 K. Calculate enthalpy change for the reaction at 298 K NH2CN(g) + 3/2 O2(g) →N2(g) + CO2(g) + H2O(I)

What is the principal function of the eyelens?

CH3 – CH2 – CH2 – CHO IUPAC name of the compound is:

Consider the reaction Cr2O7^2− +14H^+ + 6e^− →2Cr^3+ + 7H2O. What is the quantity of electricity in coulombs needed to reduce 1 mol of Cr2O7^2-? (A) 6 x 10^6 C (B) 5.79 x 10^5 C (C) 5.25 x 10^5 C (D) None of these

The displacement x of a particle at time t along a straight line is given by x = α – βt + γt^2. Find the acceleration of the particle.

A motorcyclist wants to drive on the vertical surface of a wooden wall of radius 5m, with a minimum speed of 5√5. The minimum value of coefficient of friction between the tyres and the wall of the wood must be: (Take g = 10 ms^-2) (A) 0.10 (B) 0.20 (C) 0.30 (D) 0.40

A farmer runs a pipe of internal diameter 20 cm from the canal into a cylindrical tank in his field which is 10 m in diameter and 2 m deep. If water flows through the pipe at the rate of 3 km/h, in how much time will the tank be filled?

Hydrogen atom in ground state is excited by a monochromatic radiation of λ = 975 Å. Number of spectral lines in the resulting spectrum emitted will be (A) 3 (B) 2 (C) 6 (D) 10

Find the next term of the series, 1728, 2744, 4096, 5832, 8000, 10648,? (A) 2167 (B) 13824 (C) 15625 (D) 9261 (E) 17576

Three 2 omega resistors, A, B and C are connected as shown in figure. Each of them dissipates energy and can withstand a maximum power of 18 W without melting. Find the maximum current that can flow through the three resistors?

Bad debt amount should be credited to the ___________ account (A) Debtors (B) Bad debts (C) Sales (D) Creditors

For a freely falling body the initial velocity is given by (A) v = v^2 + 2gh (B) v = gt^2 (C) v = 0 (D) None of these

The quantity of electricity required to liberate 112 cc hydrogen at STP from acidified water is ___________ (A) 965 C (B) 9650 C (C) 96500 C (D) 4825 C

Fear or excitement generally cause on to breathe rapidly and it results in the decrease of CO2 concentration in blood. In what way will it change the pH of blood? (A) pH will increase (B) pH will decrease (C) No change (D) pH will be 7

02 Sep 2021: UPSC Exam Comprehensive News Analysis

AIR Spotlight – Discussion on New Education Policy

01 Sep 2021: PIB Summary & Analysis

Why did Gandhi oppose the Communal Award?

Who was the prime minister of Britain who introduced communal award?

Who was the father of the communal electorate?

FREE TEXTBOOK SOLUTIONS