The atmospheric pressure at earth surface is P₁ and inside mine is P₂. They are related as:

1. P₁ = P₂
2. P₁ > P₂
3. P₁ < P₂
4. P₂ = 0

Simple barometer was first designed by :

1. Sir Issac Newton
2. Pascal
3. Torricelli
4. Thomas Alva Edison

At the summit of Mount Everest, the atmospheric pressure is :

1. only 40% of the atmospheric pressure at sea level
2. only 60% of the atmospheric pressure at sea level
3. only 30% of the atmospheric pressure at sea level
4. only 50% of the atmospheric pressure at sea level

Mercury is preferred as a barometric liquid because :

1. its density is high
2. its vapour pressure is negligible
3. it neither wets nor sticks to the glass
4. all of the above