Sign in
Please select an account to continue using cracku.in
↓ →
Join Our JEE Preparation Group
Prep with like-minded aspirants; Get access to free daily tests and study material.
In a typical combustion engine the workdone by a gas molecule is given by $$W = \alpha^2 \beta e^{\frac{-\beta x^2}{kT}}$$, where $$x$$ is the displacement, $$k$$ is the Boltzmann constant and $$T$$ is the temperature. If $$\alpha$$ and $$\beta$$ are constants, dimensions of $$\alpha$$ will be:
The work done is given by $$W = \alpha^2 \beta e^{-\beta x^2/(kT)}$$.
Since the exponent must be dimensionless, we analyze $$\frac{\beta x^2}{kT}$$. Here $$x$$ is displacement with dimension $$[L]$$, $$k$$ is Boltzmann constant with dimension $$[ML^2T^{-2}K^{-1}]$$, and $$T$$ is temperature with dimension $$[K]$$. So $$kT$$ has dimension $$[ML^2T^{-2}]$$.
For the exponent to be dimensionless: $$[\beta] \cdot [L^2] = [ML^2T^{-2}]$$, giving $$[\beta] = [MT^{-2}]$$.
Now, the exponential is dimensionless, so $$[W] = [\alpha^2][\beta]$$. Since $$W$$ has dimension $$[ML^2T^{-2}]$$:
$$[\alpha^2][\beta] = [ML^2T^{-2}]$$
$$[\alpha^2][MT^{-2}] = [ML^2T^{-2}]$$
$$[\alpha^2] = \frac{[ML^2T^{-2}]}{[MT^{-2}]} = [L^2]$$
Therefore $$[\alpha] = [L] = [M^0LT^0]$$.
The answer is Option 4: $$[M^0LT^0]$$.
Predict your JEE Main percentile, rank & performance in seconds
Educational materials for JEE preparation
Ask our AI anything
AI can make mistakes. Please verify important information.
AI can make mistakes. Please verify important information.