Light: Shadows and Reflections — Science STD 7 — Question

Pick the odd one out from each of the groups given below on the basis of respiratory organs. Give reason for your answer.
(a) Cockroach, grasshopper, snail, ant
(b) Lizard, cow, earthworm, snake
(c) Crocodile, whale, dolphin, fish
(d) Snake, tadpole, crow, goat

If a spoon is made of coal, what problems may arise?

Boojho made an electromagnet by winding 50 turns of wire over an Iron screw. Paheli also made an electromagnet by winding 100 turns over a similar Iron screw. Which electromagnet will attract more pins? Give reason.

Describe onsite disposal systems.

The handle of a pressure cooker is covered with the thick plastic. Explain why?

Define average speed.

Write differences between clinical thermometer and laboratory thermometer.

To keep her soup warm Paheli wrapped the container in which it was kept with a woollen cloth. Can she apply the same method to keep a glass of cold drink cool? Give reason for your answer.

How do forests help to maintain the water table?