The Mach number is defined as: A) the ratio of the stress to the strain. B) the ratio of the strain to the stress. C) the ratio of the speed of sound to the velocity of an object. D) the ratio of the velocity of an object to the speed of sound.

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?