Verified Solution • 2025–26 Session moderate

QJEEM24Ph125d: JEE Main 2024 Physics - Class 11 JEEM24Ph125d Solution: The dimensional formula of latent heat is :

The dimensional formula of latent heat is :

Multiple Choice Options

  • A [M0LT−2]
  • B [MLT−2]
  • C [M0 L2 T−2]
  • D [ML2 T−2]

Step-by-Step Verified Solution

To derive the dimensional formula of latent heat, we need to understand what latent heat actually refers to. Latent heat is the amount of heat absorbed or released by a substance during a change in its physical state (phase) that occurs without changing its temperature.

The formula for latent heat ( LL ) is given by:

Q=mLQ = mL

where:

QQ = Heat absorbed or released (with the dimension of energy [ML2T−2][\mathrm{ML}^2\mathrm{T}^{-2}] ),

mm = Mass of the substance ( [M][\mathrm{M}] ),

LL = Latent heat.

To find the dimensions of latent heat, we rearrange the formula to solve for LL :

L=QmL = \frac{Q}{m}

Knowing the dimensions of QQ (energy, which is equivalent to work done, with dimensions [ML2T−2][\mathrm{ML}^2\mathrm{T}^{-2}] ) and mm (mass, with dimensions [M][\mathrm{M}] ), we can substitute these into the equation to find LL 's dimensions:

L=[ML2T−2][M]L = \frac{[\mathrm{ML}^2\mathrm{T}^{-2}]}{[\mathrm{M}]}

This simplifies to:

L=[L2T−2]L = [\mathrm{L}^2\mathrm{T}^{-2}]

Therefore, the dimensional formula of latent heat is:

L=[M0L2T−2]L = [\mathrm{M}^0 \mathrm{L}^2 \mathrm{T}^{-2}]

So, the correct option is:

Option C [M0 L2 T−2]\left[\mathrm{M}^0 \mathrm{~L}^2 \mathrm{~T}^{-2}\right]

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