Name the device used to record earthquakes .

Name the device to measure heat.

Name the device used to measure the temperature of a body.

What is the SI unit of potential difference ? Name the device used to measure the potential difference.

What is the SI unit of potential difference ? Name the device used to measure the potential difference.

Name the modern instrument used to record blood pressure.

Mention the conditi.on under which charges an move in a conductot Name the device which is used to maintain this condition in an electric circuit