Assertion : A discharge tube appears dark when evacuted to very low pressures.
Reasoning , No Colour is left at such low pressure.

A discharge tube appears dark when evacuated to extremely low pressure . Why ?

Reaction favoured by low pressure is :

Why is a cathode ray tube evacuated to a low pressure ?

Colour in discharge tube filled with gas at low pressure is due to …

Assertion Arteries pump blood away from the heart at very low pressure. Reason Arteries have thin wall with large lumen.

What are the symptoms of low blood pressure?

Assertion An actual gas behaves as an ideal gas most closely at low pressure and high temperature. Reason At low pressure and high temperature, real gases obey the gasl laws.