PT1 SCIENCE TEST YOURSELF Cl 8
PHYSICS
I. Choose the correct option:
1) Which of the following experiences more pressure for same force?
a) Broad surface. b) Small surface. c) Horizontal surface. d) Vertical surface
2) Force is a:
a) Scalar quantity b) Vector quantity c) Constant d) Unitless quantity
3)Assertion (A): Force alone is sufficient to measure pressure.
Reason (R): Pressure depends only on force.
a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
c) Assertion (A) is true, but Reason (R) is false.
d) Both Assertion (A) and Reason (R) is false.
II. Answer the following questions:
4) Force needed to move an object greater when it is at rest compared to when it is already in motion. Explain
5)Why does a parachute slow down a falling person? Discuss the forces acting on the person.
6)Why does a tall building experience greater atmospheric pressure at its base compared to its top? Justify.
7) When a sharp knife cuts better than a blunt knife, how does pressure play a role in this difference?
CHEMISTRY
Q1. A glass tumbler kept on a burning candle, the candle gets extinguished after some time, which condition of
combustion is shown in this activity?
(a) Ignition temperature (b) fuels (c) Combustible substances (d) Oxygen
Q2. Which fire extinguisher can be used for a oil type fire?
(a) Water type (b) CO2 type (c) Foam type (d) Soda acid type
Q3. Write the principles of fire extinguisher.
Q4. Write two properties of each- (a) the hottest zone (b) the brightest zone
Q5. Draw a fire triangle and name the three conditions needed for combustion.
BIOLOGY
Q1) A combine harvester is used in the field. Which two processes are being carried out simultaneously?
(a) Sowing and irrigation (b) Harvesting and threshing
(c) Weeding and manuring (d) Storage and harvesting
Q2) Which of the following plants is commonly used as a green manure?
(a) Wheat (b) Rice (c) Sunflower (d) legumes
Q3) Assertion (A): Crop rotation helps maintain soil fertility.
Reason (R): Different crops use different nutrients from soil and rotation prevents exhaustion.
(a) Both A and R are true, and R is the correct explanation of A. (c) A is true, but R is false
(b) Both A and R are true, but R is not the correct explanation of A. (d) A is false, but R is true
Answer the following:
Q1) What are weeds? Why is it important to remove them from crop fields? Name two methods of weed control.
Q2) What is emasculation in the context of plant breeding? Why is it necessary?
Q3) Write a short note on Green Revolution? Name two high yielding varieties of wheat.
Q4) How do pesticides help in crop production? Name two precautions while using them.
