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Rainbow is an example for continuous spectrum. Explain

A rainbow is regarded as one of the most spectacular light shows observed on the earth. Rainbow is a multicoloured arc made due to the striking... View Article

Which among the following statements is incorrect for magnesium metal? (A) It burns in oxygen with a dazzling white flame (B) It reacts with cold water to form magnesium oxide and evolves hydrogen gas (C) It reacts with hot water to form magnesium hydroxide and evolves hydrogen gas (D) It reacts with steam to form magnesium hydroxide and evolves hydrogen gas

It reacts with cold water to form magnesium oxide and evolves hydrogen gas Magnesium reacts with cold water to form magnesium oxide and evolves... View Article

A cable breaks if stretched by more than 2 mm. It is cut into two equal parts. How much either part can be stretched without breaking? (A) 0.25 m (B) 0.5 mm (C) 1 mm (D) 2 mm

The elongation ΔL of a metallic cable of young modulus E, cross sectional area A and length L under the tensile load P is given by ΔL... View Article

A vendor buys bananas at 3 for a rupee and sells at 4 for a rupee. Find his profit or loss percentage

Consider the number of bananas bought = 12 Here, LCM of 3 and 4 is 12 We know that C.P. of bananas = 1/3 x 12 = ₹ 4 S.P. of bananas = 1/4 x... View Article

A large steel wheel is to be fitted on to a shaft of the same material. At 27 degree C the outer diameter of the shaft is 8.70 cm and the diameter of the central hole in the wheel is 8.69 cm. The shaft is cooled using ‘dry ice’. At what temperature of the shaft does the wheel slip on the shaft? Assume coefficient of linear expansion of the steel to the constant over the required temperature range: αsteel = 1.20 x 10^-5 K^-1

Given T = 270C This can be written in Kelvin as, 27 + 273 = 300 K Outer diameter of the steel shaft at T, d1 = 8.70 cm Diameter of the... View Article

If the radius of earth shrinks by 1.5 percent (mass remaining same), then the value of gravitational acceleration changes by (A) 2% (B) -2% (C) 3% (D) -3%

According to the question, Given Decrease in the radius of the earth is 1.5% Let the test mass used in the process is m and the mass of the earth... View Article

Write the structure of the following organic halogen compound. 2 – (2 – Chlorophenyl) – 1 – iodooctane

The structure of the given organic halogen compound is shown below... View Article

Glycogen on hydrolysis gives (A) lactose and glucose (B) only glucose (C) glucose and fructose (D) glucose and maltose

Only glucose Glycogen: It is a multibranched polysaccharide of glucose that serves as a source of energy in animals.These carbohydrates are... View Article

___________ is considered as the father of Socialism

Karl Marx revolutionized and popularized the ideas of Socialism. Therefore, he is called as the father of modern socialism... View Article

A proton of energy 8 eV is moving in a circular path in a uniform magnetic field. The energy of an alpha particle moving in the same magnetic field and along the same path will be (A) 4eV (B) 2eV (C) 8eV (D) 6eV

Given Energy of a proton = 8eV Here, Momentum of a particle moving in a magnetic field mv = p = qBr Hence, Kinetic energy of that particle can be... View Article

A depleting source of energy is (A) Wind (B) Sunlight (C) Water (D) Fossil fuels

A depleting source of energy is fossil fuels. Fossil fuels are buried flammable geologic deposits of organic substances such as dead plants and... View Article

Find the zeroes of the following polynomial 5x^2 – 4 – 8x and verify the relationship between zeros of the polynomial and the coefficients of the polynomial

Given polynomial is 5x2 - 8x - 4 = 5x2 - 10x + 2x - 4 = 5x (x - 2) + 2 (x - 2) = (5x + 2) (x - 2) Hence, the value of 5x2 - 8x - 4 = 0 when... View Article

Use Euclid’s Division Algorithm to find the HCF of 726 and 275

HCF of 726 and 275 726 = 275 x 2 + 176 275 = 176 x 1 + 99 176 = 99 x 1 + 77 99 = 77 x 1 + 22 77 = 22 x 3 + 11 22 = 11 x 2 + 0 Therefore,... View Article

Let x and a stand for distance. Show that ∫dx/√(a^2-x^2)=1/a sin^-1 a/x dimensionally correct

Dimension on the left side = ∫dx/√(a2-x2)= [L0] Dimension on the right side = 1/a sin-1 (a/x) = [L-1] So, dimension of LHS... View Article

Deuteron and alpha particle are put 1 A apart in air magnitude Å apart in air. Magnitude of intensity of electric field due to deuteron of alpha particle is (N/C) (A) Zero (B) 2.88 x 10^11 N/C (C) 1.44 x 10^11 N/C (D) 5.76 x 10^11 N/C

Electric field = 1/4πε0 x q/r2 E = 9 x 109 q/r2 E = 9 x 109 x 1.6 x 10-19/(1 x 10-10)2 On further calculation, we get, E = 1.44 x... View Article

In earthworm gizzard is found in (A) Eighth to tenth segment (B) Eighth segment (C) Twenty-seventh segment (D) Eighth to eleventh segment

Eighth segment The digestive system of earthworm consists of the pharynx, the esophagus, the crop, the intestine and the gizzard. In the eighth... View Article

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