What value should come in the place of (?) in the

Which one of the following wave- lengths of light is most effective in photosynthesis?

Up to what temperature can a mercury thermometer measure?

The force required to maintain an object at a constant velocity is

Main function of leaf is

Which among the following is produced using ‘Haber Process’?

The electrical conductivity of a semiconductor increases with rise in temperature because:

Which of the following elements have the lowest and highest boiling point in the Periodic table?

Which of the following is the hardest substance known?

Minamata disease, a neurological disorder, is caused by eating fish contaminated with which element?

Which among the following are unisexual flowers?