Q1.An electric lamp of 100 watt is used for 10 hours per day. The ‘units’ of energy consumed in one day by the lamp is
(a) 1 unit
(b) 0.1 unit
(c) 10 units
(d) 100 unitsQ2. Imagine a current carrying wire with the direction of current downward or into the page. The direction of magnetic field lines is
(c) into the page
(d) out of the pageQ3. 8. How long does it take light from the sun to reach to the earth (approximately)?
(a) 2 min
(b) 4 min
(c) 8 min
(d) 16 min Q4. When X-rays are produced
(a) heat is generated at the target
(b) heat is absorbed at the target
(c) the temperature of the target remains constant
(d) brilliant light is seen at the targetQ5. Which one of the following substances does not have a melting point?
(b) Sodium chloride
(d) Glass Q6. Which one of the following elements is a metalloid?
(d) Po Q7. Which among the following is a chemical change?
(a) A wet towel dries in the sun
(b) Lemon juice added to tea causing its colour to change
(c) Hot air rises over a radiator
(d) Coffee is brewed by passing steam through ground coffeeQ8. Which one among the following is correct regarding 20Ne, 23Na+, 19F – and 24Mg2+?
(a) They are isomers of each other
(b) They are isotopes of each other
(c) They are isoelectronic with each other
(d) All of the aboveQ9. Which gas is responsible for the swelling of bread?
(b) Carbon monoxide
(c) Carbon dioxide
(d) Ammonia Q10. Which of the following statements about diamond are correct?
1. It is used as a gem in jewellery because of its ability to reflect light.
2. It is good conductor of electricity.
3. It is used for cutting glass, marble stones and other hard materials.
4. It is used for drilling of rocks.
Select the correct answer using the codes given below
(a) 1, 3 and 4
(b) 2, 3 and 4
(c) 1, 2 and 3
(d) 2 and 4Q11. Which of the following is not a nitrogenous fertilizer?
(d) Urea Q12. Which one of the following elements will replace hydrogen from acids to form salts?
(b) Silicon (Si)
(c) Zinc (Zn)
1. (a)2. (b)3. (c)4. (a)5. (c)6. (c)7. (d)8. (c)9. (c)10. (d)11. (a)12. (c)