CBSE Pathshala

1. Bio gas is also known as gobar gas. Justify. 2. Name the instrument used to measure electric current in a circuit. 3. The charge possessed by an electron is 1.6x10 -19 coulombs. Find the number of electrons that will flow per second to constitute a current of 1 ampere. 4. What are permanent magnets and electromagnets? Give one use of each. 5. Explain the role of fuse in series with any electrical appliance in an electric circuit? Why should a fuse with defined rating for an electric circuit not be replaced by one with a larger rating   6. (a) Charcoal is a better fuel than wood. Why ? (b) How does biogas plant help to reduce the problem of pollution?

Q.1. find the mean of the following frequency distribution: - Ans. 25.2 (2) Class 0-10 10-20 20-30 30-40 40-50 Frequency 8 12 10 11 9 aQ.2. find the mode of the following data. Ans.52 (2) Class 0-20 20-40 40-60 60-80 Frequency 15 6 18 10 Q.3. the mean of the following frequency distribution is 50. Find the value of P. Ans.P=52 (3) Class 0-20 20-40 40-60 60-80 80-100 Frequency 17 28 32 P 19 Q.4. compute the median. Ans. 46.5 (3) Weight in (kg) Less than 38 Less than 40 Less than 42 Less than 44 Less than 46 Less than 48 Less than 50 Less than 52 Number of ...