Why does a heat pump need an external source
of energy (such as electrical energy) ?

The reason is because a heat pump uses external power to accomplish the work of transferring energy from the heat source to the heat sink. Heat pumps are significantly more energy efficient than simple electrical resistance heaters. The efficiency begins to decrease as the temperature difference between the heat source and sink increases.

the largest known star in the universe is uy scuti, a hypergiant with a radius around 1,700 times larger than the

u can delete ur account.

1. go on google and write

2 open this and click on your profile pic and if your profile is not appearing, then u have to log in.

3. when u click on your profile pic, there appears four options on the top.

4. click on the 1st option and scroll down and go at the bottom.

5. click on edit profile.

6. there appears a option 'prefernces' and at that option at the right side , 'edit' is written.

7. click on the edit option.

8. there is a option " i want to delete my account" and click on that.

hope this u

and ur welcm

: )