Question

17. The difference between coal and coke is (A) Coal is a mineral while coke is a residue (B) Coal is an impure form of carbon, coke is a pure form carbon (C) Coal consists of atoms of carbon, hydrogen, oxygen and Sulphur, while coke is 98% carbon (D) All of the above 18. On the basis of following features identify the correct fibre. 1. They are very fine strand of pure glass 2. These fibres are used in making medical equipment 3. These fibres are used to transmit messages in modern communication (A) Optical fibre (B) Glass fibre (C) Blended fibre (D) Polyester fibre
20. Vijay took a piece of burning charcoal and collected the gas evolved in a test tube. The

gas settle at the bottom of the test tube. Which one of the following conclusion is correct

about the gas collected?

(A) Gas evolved is basic and heavier than air

(B) Gas evolved turns a wet blue litmus red and heavier than air

(C) Gas evolved turns a wet red litmus blue and heavier than air

(D) Gas evolved is acidic and lighter than air
22. Study the following statements and select the correct option

Statement 1: Thermoplastic can be moulded

Statement 2: They do not undergo any change in their composition when they are

heated and remoulded

(A) Statement 1 is correct but statement 2 is incorrect

(B) Statement 1 is incorrect but statement 2 is correct

(C) Both statements are incorrect

(D) Both statement are correct

23. When a metal corrodes in water, it forms

(A) Metal hydroxide and hydrogen (B) Rust and Carbon dioxide

(C) Salt and water (D) Salt and hydrogen

24. If we collect the residue after burning magnesium and add water to it. The solution

would

(A) turns blue litmus red (B) turn red litmus blue

(C) be neutral to litmus (D) dissolves the litmus paper
25. Identify X from the following information

1. X is lighter than air

2. X mainly consists of a gas called methane

3. X is mainly found under the ground near petroleum

(A) Coal gas (B) Water gas

(C) Natural gas (D) Petroleum gas

26. Which of the following is displacement reaction?

(A) PCl5 PCl3 + Cl2

(B) 2KIO3 + Cl2 2KClO3 + I2

(C) 2SO2 + O2 2SO2

(D) 2SO2 + O2 +2H2O 2H2SO4
29. Petrol is a secondary fuel because

(A) petrol is in liquid state (B) petrol is obtained from the nature

(C) petrol is synthesized from petroleum (D) petrol is used in light vehicles
32. Which one of the following statements is correct?

(A) Only the egg cell has a nucleus.

(B) The skin cell has no genetic information in its chromosomes.

(C) The egg cell has as many chromosomes as the skin cell

(D) The skin cell has twice as many chromosomes as the egg cell.
36. Which of the following correctly describes bacteriophage?

(A) It is bacterium which causes diseases in plants

(B) It is a virus which attacks bacteria

(C) It is a bacterium which kills viruses

(D) It is virus which can multiply inside of both living & non living organisms​

Answer 1

Answer:

17. A) coal is a mineral while coke is a residue