Question

Ampere - hour is the unit of:
A.) Power
B.) Energy
C.) Quantity of electricity
D.) Strength of current

Answer 1

Hint: Use principle of Homogeneity and remember that rate of flow of charge through a point is known as current.

Formula used: $I = \dfrac{Q}{t}$ Here Q is the charge flowing through a point at a time period t.

Complete step by step solution:
We know Ampere is a unit of current and its dimension is ${M^0}{L^0}{T^0}{A^1}$
So dimension of Ampere hour is ${M^0}{L^0}{T^1}{A^1}$

Also, since current $I = \dfrac{Q}{t}$ ; $Q = I \times t$

we can see that charge and Ampere hour has a same dimension of ${M^0}{L^0}{T^1}{A^1}$
Using the principle of homogeneity we can say that Ampere hour represents the amount of charge.

Just like how mass is a measure of the amount of matter in a system, charge can be seen as a measure of the amount of electrified matter or the Quantity of electricity present in the system.

So we can conclude that ampere hour is a measure of quantity of electricity (which is equivalent to the amount of electric charge)

Thus, the correct option is C.

Additional Information:

The SI unit of charge is coulomb.

1 ampere hour is the amount of charge transferred if 1A current passes through a region for 1hour.

Since coulomb represent the flow in seconds

1 Ampere hour $ = 60 \times 60C$

$1Ah = 3600C$ (Ah is a symbol used for ampere hour.)

Note: The principle of homogeneity is not true for all cases .Since the ratios, constants, or trigonometric quantities have no dimension, their presence or absence in an equation cannot be determined.
Also, sometimes comparing dimensions would not give a correct significance of a quantity. For example: Though Torque and Energy have the same dimension, we cannot say - Joules represent the Moment of force on a body.