Which of the following is NOT a SI unit?

The correct answer is Calorie.

Key Point

• The concept of Calory:
  • Calorie, a unit of heat energy in the metric system.
  • The measurement of heat is called calorimetry.
  • The calorie, or gram calorie, is the quantity of heat required to raise the temperature of 1 gram of pure water 1°C.
  • The kilocalorie is used in dietetics for stating the heat content of a food, i.e., the amount of heat energy that the food can yield as it passes through the body; in this context, the kilocalorie is usually called simply the calorie.
  • The amount of heat energy needed to effect a 1°C temperature increase in 1 gram of water varies with temperature (see heat capacity); thus the temperature range over which the heating takes place must be stated to define the calorie precisely.
  • The 15° calorie, or normal calorie, is widely used in chemistry and physics; it is measured by heating a 1-gram water sample from 14.5°C to 15.5°C at 1-atmosphere pressure.
  • The 4° calorie, also called the small calorie or therm, is measured from 3.5°C to 4.5°C (water is most dense at 3.98°C); the large calorie, or Calorie, is equivalent to 1,000 small calories.
  • The average value of the calorie in the range 0°C to 100°C is called the mean calorie; it is  1⁄100 of the energy needed to heat 1 gram of water from its melting point to its boiling point.
  • The calorie may also be defined by expressing its value in some other energy units.

 Additional Information

•  Ohm
  • Ohm is denoted by symbol Ω. It is the Greek letter omega.
  • This is named after Georg Simon Ohm, a German physicist who studied the relationship between voltage, current, and resistance.
  • Resistance is the measurement of the opposition to current flow in an electrical circuit.
  • It is also defined as the ratio of the voltage applied to the electric current which flows through it.
  • The resistance of a material is directly proportional to the length and inversely proportional to the area of cross-section. It is also directly proportional to the resistivity of the material.
  • Conductors have less resistance and that is why current can flow easily through it. Insulators have high resistance and that is why current can not flow easily through it.
  • Ohm's law states that the electric current is proportional to voltage and inversely proportional to resistance. It is represented by V=IR.​
• ​Newton
  • Newton is the SI unit of force. And force equals the product of mass and acceleration.
  • SI unit of force = Newton
  • SI unit of mass = kg
  • SI unit of acceleration = m.sec-2.
  • Hence, 1 Newton is equals to, kg m.sec-2  . the other units do not satisfy the unit of Newton.