Hydrous ferrous sulphate crystals are heated in a boiling tube for few seconds. Water droplets are seen in the inner sides of test tube and the colour of the crystals changes. On continuous heating a colourless gas X with smell of burning sulphur is evolved and a residue Y is obtained. What is the colour of the crystals before and after mild heating?

What type of questions asked from the lesson of magnetic effect of electric current 

Wavelength of green light is

A) 400-450 nm

B) 500-550 nm

C) 660-720 nm

D) 720-800 nm

What is the difference between anaerobic & aerobic respiration? Name some organism that uses the aerobic mode of respiration?

What are the main components of our environment? Explain each of them briefly.

What are examples of hydrotropism plants?