Which of the following in the correct device that

Sound and light waves both have ___________ .

The instrument which uses sound waves to measure the depth of oceans is –

What is the audible frequency range?

What is the SI unit for measuring electric current?

Which type of mirror is utilized in solar furnaces to focus sunlight and generate heat?

Panchayat was added to our constitution through which amendment? 

The S.I. unit of the electric flux is

Which Metal is found in the highest proportion in earth’s crust?

Among the following, which has the lowest density?

Which instrument is commonly used to measure atmospheric pressure?