- (A) α-particle emission from a radioactive element makes it electrically negative
- (B) β-particle emission from a radioactive element makes it electrically positive
- (C) A radioactive element having a half life period of 20 years will completely disintegrated in 40 years
- (D) The disintegration constant of a radioactive isotope is independent of pressure, temperature or concentration
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- (A) Atoms with same number of nucleons but different number of protons are called isobars
- (B) Atoms with same number of protons but different number of nucleons are called isoters
- (C) Out of α, β, and γ-rays, the one having maximum penetration power are γ-rays
- (D) The product formed by emission of α-particle has mass number less by 4 units than the parent nuclide
- (A) The nucleus of a hydrogen atom is identical with a proton
- (B) A, β-ray particle is identical with an electron
- (C) Mass of an electron is about 1/1800th of the lightest nucleus
- (D) Positron is heavier than a proton
- (A) The ratio of the density of the ‘nucleus’ to that of the ‘atom’ is 1012
- (B) α-particle is identical with a doubly charged helium ion
- (C) The mass of deuterium atom is half that of helium atom
- (D) Gamma rays are high energy electrons
- (A) Positron is the antiparticle of electron
- (B) In α-decay, the ratio of neutron to proton decreases
- (C) Ionising power of β-rays is higher than that of α-rays
- (D) Speed of α-rays is more than that of γ-rays
- (A) Loss of electrons from neutral atoms produces negative ions
- (B) The radius of nucleus & atomic size are of the order of 10-12 cm & 10-8 cm respectively
- (C) Gain of electrons by neutral atoms form cations
- (D) Proton to neutron ratio in a stable nucleus is 2 : 1
- (A) The disintegration rate of a radioactive substance cannot be increased by heating it
- (B) Electrons have negligible mass and unit negative change
- (C) Deuterium atom has one proton and two neutrons in its nucleus
- (D) Cadmium is capable of absorbing neutrons
- (A) Multigrade lubricating oils have high viscosity index
- (B) Paraffinic oil has very high viscosity index
- (C) Naphthenic oil has very low viscosity index
- (D) High viscosity index means a large change in viscosity with change in temperature
- (A) Clausius-Clapeyron equation relates the latent heat of vaporisation to the slope of the vapor pressure curve
- (B) At the boiling point of liquid at the prevailing total pressure, saturated absolute humidity is infinite
- (C) Percentage saturation and relative saturation are numerically equal for an unsaturated vapor gas mixture
- (D) Clapeyron equation is given by dP/dT = (λ/T) (VG – VL); where, P = vapor pressure, T = absolute temperature, λ = latent heat of vaporisation, VG and VL = volumes of gas and liquid respectively
- (A) To make 100 kg of a solution containing 40% salt by mixing solution A (containing 25% salt) and solution B (containing 50% salt), the amount of solution A required is 40 kg
- (B) 1.2 gm atoms of carbon and 1.5 gm moles of oxygen are reacted to give 1 gm mole of carbon dioxide. The limiting reactant is carbon. The percent excess reactant supplied is 25
- (C) A gas bubble at a pressure of Pg is passed through a solvent with a saturation vapour pressure of Ps. If the time of passage of the bubble is long and air is insoluble in the solvent, the mole fraction of solvent in the bubble will be equal to Ps/Pg
- (D) A supersaturated solution of a sparingly soluble solute, at a concentration of C, is being fed to a crystalliser at a volumetric flow rate of V. The solubility .of the solute is C1. The output rate of solids from an efficient crystalliser is (C + C1) V
