CBSE Sample Paper 2021 Class 7 Science Half Yearly
Half Yearly Examination (2020-21)
Time: 2:30 hours
All questions are compulsory.
1- Multiple Choice Questions.(1 x 6 = 6)
i- Which of the following is a mineral acid?
a) Sulphuric acid
b) Citric acid
ii- Which food item contains ascorbic acid?
iii- Which of these is not a base?
iv- The small air sacs in the lungs are called
v- Fish exchange gases through
vi- Exchange of gases in insects take place through
2- State ‘T’ for True and ‘F’ for False Statements from the following.(1 x 8 = 8)
i – Tearing of paper is a physical change.
ii – A physical change can be reversed.
iii- The presence of oxygen and water is necessary for rusting of iron.
iv- Vinegar is dilute lactic acid.
v- The chemical name of vitamin D is ascorbic acid.
vi – Acid feel slippery to touch.
vii- Copper is more reactive than iron.
viii- In a chemical change no new substance is formed.
3- Fill in the blanks.(1 x 8 = 8)
i- A___________ is a person who studies the weather.
ii- ___________ usually huddle together.
iii- ___________body helps a polar bear to swim.
iv- The Earth’s weather is driven by the___________.
v- Air around us exerts___________.
vi- Air___________ on heating and contracts on___________.
vii- ___________speed winds are accompanied by reduced air pressure.
viii- The ___________air is called wind.
4- Match the following(1 x 5 = 5)
i) A horizon Solid rock
ii) B horizon Broken rock
iii) C horizon Litter
iv) R horizon Humus
v) O horizon Subsoil
5- Define the following.(4 x 2 = 8)
6- Short answer type questions.(8 x 2 = 16)
i) What is tornado?
ii) What is meant by the ‘eye’ of a cyclone?
iii) What are monsoon winds?
iv) Write two causes of soil erosion.
v) Name the different types of soils.
vi) What does soil consists of?
vii) How do earthworms respire?
viii) Why does air rush into your body when you inhale?
7- Long answer type questions.(6 x 4 = 24)
i) Explain the difference between breathing and respiration.
ii) What do you mean by percolation rate of water? How will you calculate it?
iii) How do high-speed winds result in reduced air pressure?
iv) What precautions are needed in the cyclone-prone areas?
v) List the factors that affect the climate of a place.
vi) What are bases? Explain their characteristics properties.
8- Draw a labelled diagram of Human respiratory system. (5 x 1=5)
Draw a labelled diagram of composition of soil.