Match the given quantities with their corresponding units or values.

Quantities		Corresponding units or values
a.	1 kilowatt hour	i.	watt
b.	Unit of electric energy	ii.	3.6 x 106 joule
c.	Unit of power	iii.	watt-sec
		iv.	106 joule

The correct answer is Option 1: (a)-(ii), (b)-(iii), (c)-(i).

Key Points

• 1 kilowatt hour is equivalent to 3.6 x 10⁶ joule (option ii).
• The unit of electric energy is commonly expressed in terms of watt-second (or joule) (option iii).
• The unit of power is the watt, which is the rate of energy transfer (option i).
• Thus, the correct matching is:
  • (a) - (ii): 1 kilowatt hour = 3.6 x 10⁶ joule
  • (b) - (iii): Unit of electric energy = watt-sec
  • (c) - (i): Unit of power = watt

Additional Information

• Kilowatt hour (kWh):
  • It is a measure of energy commonly used in billing electricity consumption.
  • 1 kWh = 1 kilowatt (1000 watts) of power used for 1 hour.
  • It is equivalent to 3.6 x 10⁶ joules.
• Watt:
  • The watt (W) is the SI unit of power.
  • 1 watt = 1 joule per second (1 W = 1 J/s).
  • It measures the rate at which energy is transferred or used.
• Joule:
  • The joule (J) is the SI unit of energy.
  • 1 joule is the energy transferred when 1 watt of power is applied for 1 second (1 J = 1 W·s).
• Electric Energy Units:
  • Electric energy is often measured in watt-seconds, joules, or kilowatt-hours.
  • In practical usage, kilowatt-hours are preferred for larger scales like household electricity consumption.