Question

Unit used in selling electrical energy to consumer
a. Volt – ampere
b. Kilowatt-hour
c. Volt/second
d. None

Answer 1

Hint: The joule or watt second is the unit of electrical energy. If one ampere of current for a second flows through the circuit and the potential difference of one volt is applied across the circuit then the electrical energy of the circuit is one joule. The movement of charged particles along or through a wire produces current or electricity. Electrical energy produces because of either potential energy or kinetic energy.it is the scalar quantity.

Complete step by step answer:
Kilowatt-hour that is kWh is the Commercial unit of electrical energy. 1 unit of energy is equal to 1 kWh.
To convert 1 kWh into joule
Put kilowatt as \[1000\] and $1$ hour is equal to $60$ minutes and $60$ seconds
Then, multiplying values in RHS
$1$ kWh = \[1000{\text{ }} \times {\text{ }}60{\text{ }} \times {\text{ }}60J\]
Multiplying,
$1$ kWh = \[3600000J\]
Hence,
$1$ kWh = \[3.6{\text{ }} \times {\text{ }}{10^6}J\]
SI unit (International System of units) of electrical energy is joule. kWh is used in measuring electric energy in factories, industries and houses.

Hence, the correct answer is option (B).

Additional information:
A volt-ampere is a unit used for the apparent power in an electrical circuit. The apparent power equals the product of root mean square voltage and root mean square current. In direct current circuits, this product is equal to the real power in watts. Volt-amperes are usually used for analyzing alternating current circuits. The volt-ampere is dimensionally equivalent to the watt. Volt-ampere rating is most useful in rating wires and switches for inductive loads.

Note: Rate of doing work is called power. Electricity is measured at Watts. Watt-hour (Wh) is equal to one Watt.
Example of electrical energy is lightning. Lightning is discharging electricity in the atmosphere.
It is used in electrical appliances, computers, machineries, domestic appliances.
Electric power, ${\text{P = VI}}$.
V is a potential difference, I is current and P is the power.
Electricity generation is also measured such as megawatts (MW) and gigawatts (GW)
Commercial unit of energy is also termed as B.O.T. (Board of Trade).