CBSE BOARD SAMPLE PAPER – SCIENCE

( PHYSICS QUESTIONS SEPARATED OUT)

                                                                         PAPER – I

Q2. Name any two isotopes which readily undergo nuclear fission. 1

Q4. Why does it take longer to burn wet wood? 1

Q6. Define the terms

(a) Astronomical Unit

(b) Light year

Give approximate value of each in SI units. 2

Q8. Calculate the energy released ( in MeV) when 1 kg mass is completely converted into

energy. (Take 1 MeV = 1.6 x10-13 J, C = 3.0 x 108 ms-1) 2

OR

When Uranium undergoes fission, 0.1% of the total mass is converted into energy.

Calculate the total amount of energy released in Joules during an explosion of an atom

bomb which contains 5 kg of Uranium.

Q10. State Right Hand Thumb rule to find the direction of the magnetic field around a current

carrying straight conductor. How will this magnetic field be affected on?

(a) increasing the current through the conductor?

(b) changing the direction of flow of current in the conductor? 2

Q12. Two identical resistors, each of resistance 10 ohms, are connected (i) in series (ii) in

parallel, in turn, to a battery of 6 volts. Calculate the ratio of power consumed in the

combination of resistors in two cases. 3

Q14. Draw a labeled diagram of a dry cell. Write the chemical equations involved

i) at the anode

ii) at the cathode

while the cell is working. 3

Q15. Distinguish between polar and equatorial orbits of artificial satellites. Which of the above

two orbits is suitable for a

(i) geostationary satellite

(ii) satellite used for weather forecasting? 3

OR

How do we locate the position of the pole star in the sky? Why is the pole star so special?

Q18. Biogas technologies are gaining acceptance by both rural and urban population. Why?

What is biogas? How is it obtained from cow dung? Draw a labelled diagram of a fixed

dome type biogas plant. 5

OR

What is meant by the term ‘refining of petroleum’? Draw a labeled diagram of petroleum

distillation tower. Why is CNG considered an environment friendly fuel?

Q20. Explain Myopia with the help of suitable ray diagrams. How can this defect of vision be

corrected?

A boy uses spectacles of focal length –50 cm. Name the defect of vision he is suffering

from. Compute the power of this lens. 5