Ordinary cells can convert chemical energy to electrical energy only, but rechargeable cells can also store electrical energy into chemical energy and vice versa. You will study more about it in your higher classes. secondary cells can be recharged and used again but dry cells cannot be recharged.
Answer:
11. Depression
Explanation:
11. Many people face depression and don't know how to fix or deal with the problem in a healthy way.
12. It can be controlled by the stuff you eat for example if you don't eat lunch you may be hungry which is bad plus the depression.
Answer:
D. The frequency is not affected as the volume of sound increases
Explanation:
Volume of the sound is defined by the amplitude of the wave or how loud a sound is whereas Frequency is basically the pitch of the sound and is inversely proportional to the wavelength . Increasing frequency will increase the pitch of the sound without affecting it's volume.