Q1.Silver gets corroded due to ________________ in air.
(b) Hydrogen Sulphide
(c) Carbon dioxide
Q2.Which of the following is a radioactive element?
Q3.Which of the digestive organs contains acid?
(b) Small intestine
Q4.Which of the following fibres is considered as the strongest natural fibre?
Q5.Purpose of an optical filter is to : ________
(a) reflect lights of different colours
(b) dispense light into component colours
(c) refract light of different colours
(d) transmit or absorb light of different colours
Q6.Silica gel is a—
(b) flavouring agent
(c) drying agent
(d) delicious food
Q7.Biofertilizers convert nitrogen to _________ .
(d) amino acids
Q8.Silk worms feed on—
(a) Basil leaves
(b) Curry leaves
(c) Rose leaves
(d) Mulberry leaves
Q9.What is the product formed when sodium bicarbonate is heated strongly?
(a) Sodium Carbonate
(b) Sodium Hydroxide
(c) Sodium Peroxide
(d) Sodium Monoxide
Q10.The sexual reproductive organs of aspergillus are:
(a) Spermatium and Oogonium
(b) Antheridium and Oogonium
(c) Spermatium and Ascogonium
(d) Antheridium and Ascogonium
Q11.Stars twinkle but planets do not twinkle because—
(a) they emit light of a constant intensity
(b) their distance from the earth does not change with time
(c) they are very far away from the earth resulting in decrease in intensity of light
(d) they are nearer to the earth and hence we receive a greater amount of light and therefore minor variations in intensity are not noticeable
Q12.Which of the following is not true about X-rays?
(a) have low penetrating power
(b) travel with the speed of light
(c) Can be reflected or refracted
(d) can affect photographic plates
Q13.Which one of the following weeds is effective in controlling water pollution caused by industrial effluents?
(b) Elephant grass
(c) Water hycinth
(d) Mogar grass
Q14.Sullage water is ______
(a) Waste water released from kitchen
(b) waste water released from toilets
(c) waste water released from factories
(d) waste water released from hospitals
Q15.The most pure form of carbon among the options is
(d) Wood Charcoal