Answer:a
Explanation:
We have to lift the load two loads up one story, so energy required is
let m be the mass of each load and h is the height of each story
Energy 
Here energy gained is the potential energy which depends upon the datum(floor).
For lifting one load up one story
Energy required
thus 
is half of 
So option a is correct
ATM is not the following example of units for expressing pressure
Explanation:
The emf is equal to the work done on the charge per unit charge (ϵ=dWdq) when there is no current flowing. Since the unit for work is the joule and the unit for charge is the coulomb, the unit for emf is the volt (1V=1J/C).
Answer:
Substances can change phase—often because of a temperature change. At low temperatures, most substances are solid; as the temperature increases, they become liquid; at higher temperatures still, they become gaseous. The process of a solid becoming a liquid is called melting.
Answer:
This is an open circuit
Explanation:
An open circuit I believe
It needs to be closed for the bulb to be turned on
