Which one the following can be used to confirm whether drinking water contains a gamma emitting isotope or not?
(b) Lead plate
(c) Scintillation counter
Scintillation counter is a device used to detect the radioactive isotope. Generally alpha, beta, gamma rays emitted from radioactive substance emits radiation on scintillation counter.
Which one of the following is a mixed fertilizer?
(c) Ammonium sulphate
NPK- contains nitrogen, phosphorus and potassium in different percentage. It is an ideal mixture of fertilizers.
Which one of the following polymers is widely used for making bullet proof material?
(a) Polyvinyl chloride
Polycarbonates are the polymer widely used in making bullet proof jacket forms with different layers of substance, which provide resistance in penetrating from bullet.
The chemical used as a ‘fixer’ in photography is:
(a) Sodium sulphate
(b) Sodium thiosulphate
(c) Ammonium persulphate
Sodium thiosulphate is used as a fixer in photography. It removes Ag from negative by forming complex with it.
Which one of the following pairs of materials serves as electrodes in chargeable batteries commonly used in devices such as torchlights, electric shavers etc?
(a) Nickel and cadmium
(b) Zinc and carbon
(c) Lead peroxide and lead
(d) Iron and cadmium
‘yellow cake’, an items of smuggling across border is:
(a) A crude form of heroin
(b) A crude form cocaine
(c) Uranium oxide
(d) Unrefined gold
Uranium oxide smuggled across border as yellow cake. Enriched uranium can be used in making illegal nuclear explosive that is dangerous to humanity.
The difference between a nuclear reactor and an atomic bomb is that
(a) No chain reaction takes place in nuclear reactor and an, while in the atomic bomb there is a chain reaction
(b) The chain reaction in nuclear reactor is controlled
(c) The chain reaction in nuclear reactor is not controlled
(d) No-chain reaction takes place in atomic bomb, while it takes place in nuclear reactor
The main difference between a nuclear reactor and an atomic bomb is that the chain reaction in nuclear reactor can be controlled, whereas in nuclear bomb chain reaction goes uncontrolled.
Which one of the following fuels causes minimum environmental pollution?
Diesel, coal and kerosene have high carbon percentage, which on burning forms oxide of carbon, such as CO2, CO but hydrogen after oxidation only forms water and water is not a pollutant anyway.
Physic-chemical characteristics of water in water sources undergo changes due to:
(a) Aquatic macrophytes
(b) Aquatic fungi
Aquatic macrophytes, aquatic fungi are natural organism and evapotranspiration is a natural process by which plant losses water. Effluents from various industrial units and sewage are the culprits which change the physico-chemical characteristics of water.
The alpha particle carries two positive charges. Its mass is very nearly equal to that of:
(a) Two protons
(b) An atom of helium
(c) Sum of messes of two positrons and two neutrons
(d) Two positrons as each positron carries a single positive charge
Each alpha particle contains two protons and two neutrons, so its mass is equal to the atom of helium. The molecular weight of the helium atoms is 4 same as of alpha particle.