Latent heat is energy per unit mass, so its dimensional formula is derived by dividing energy (\( [M L^2 T^{-2}] \)) by mass (\( [M] \)), giving \( M^0 L^2 T^{-2} \).
Step 1: {Define latent heat}
Latent heat (\( L \)) is defined as the amount of heat energy (\( Q \)) required to change the phase of a substance per unit mass:
\[
L = \frac{Q}{m}
\]
Step 2: {Determine the dimensional formula of \( Q \)}
Heat energy (\( Q \)) is a form of energy, and its dimensional formula is the same as that of work:
\[
[Q] = [M L^2 T^{-2}]
\]
Step 3: {Determine the dimensional formula of \( L \)}
Since mass (\( m \)) has the dimensional formula:
\[
[m] = [M]
\]
we divide:
\[
[L] = \frac{[Q]}{[m]} = \frac{[M L^2 T^{-2}]}{[M]}
\]
\[
= M^0 L^2 T^{-2}
\]
Step 4: {Verify the options}
Comparing with the given choices, the correct answer is (C) \( M^0 L^2 T^{-2} \).
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Approach Solution -2
Given:
We are to find the dimensional formula of latent heat.
Step 1: Definition of latent heat
Latent heat (L) is defined as the amount of heat required to change the phase of a unit mass of a substance without any change in temperature.
\[
L = \frac{Q}{m}
\]
Where:
- \( Q \) = heat energy (dimensions of energy)
- \( m \) = mass
Step 2: Write dimensions
- Heat energy \( Q \) has dimensions of work or energy: \( [ML^2T^{-2}] \)
- Mass \( m \) has dimension: \( [M] \)
So,
\[
[L] = \frac{[ML^2T^{-2}]}{[M]} = [M^0 L^2 T^{-2}]
\]
Final Answer:
The dimensional formula of latent heat is \( \boxed{[M^0 L^2 T^{-2}]} \)