Explanation

The SI unit of electric charge is the coulomb, represented by the symbol C.

One coulomb is the amount of charge that passes through a conductor carrying one ampere of current for one second.

It's also equal to the charge of about 6.24 quintillion electrons or protons.

Explanation

 A calorie is a unit of energy, specifically used to measure heat energy.

1 calorie is the amount of heat required to raise the temperature of 1 gram of water by 1°C.

In dietary terms, we use kilocalories (kcal) — where 1 kcal = 1000 calories — but it still measures energy, not diet or food itself

Explanation

 The SI unit of heat is the joule (J).

Heat is a form of energy

And the joule is the standard unit for energy in the International System of Units (SI).

For instance, 1 joule of heat is the energy required to raise the temperature of 1 gram of water by 0.24°C. 

Explanation

A voltmeter is used to measure the potential difference (voltage) across two points in a circuit.

It is connected in parallel with the component whose voltage is being measured.

Explanation

The ampere, symbol A, is the SI unit of electric current.

It is defined by considering the fixed  value of the elementary charge e as 1.602 176 634 x 1019,

where the unit C is equal to As and the second is defined by Δν Cs.