The actual amount of water vapour present in the atmosphere is

1. Actual vapour
2. Absolute humidity
3. Relative humidity
4. Humidity

The atmospheric pressure at the sea level is

1. 1013 gm/sq cm
2. 4301 gm/sq cm
3. 1034 gm/sq m
4. 4301 km/sq cm

Lines on weather map joining places having equal pressure are called

1. Isohyets
2. Isohales
3. Isobars
4. Isotherm

Scales measuring the force of winds at sea

1. Primary scale
2. Verbal scale
3. Beaufort scale
4. Statement scale