List - I List - II A. Meter (L) I. $\sqrt{\frac{hc}{G}}$ B. Second (S) II. $\sqrt{\frac{Gh}{c^{5}}}$ C. Kilogram (M) III. $\sqrt{\frac{K^{2}L^{2}c^{3}}{Gh}}$ D. Kelvin (K) IV. $\sqrt{\frac{Gh}{c^{3}}}$
where h (Planck's constant), G (gravitational constant) and c (speed of light in vacuum) as fundamental units.
Choose the correct answer from the options given below :
This problem requires matching fundamental units from List-I with expressions from List-II based on dimensional analysis. We first establish the dimensions of the fundamental constants provided:
We calculate the dimensions for each expression in List-II:
Dimension calculation:
$\sqrt{\frac{[M L^2 T^{-1}][L T^{-1}]}{[M^{-1} L^3 T^{-2}]}} = \sqrt{\frac{[M L^3 T^{-2}]}{[M^{-1} L^3 T^{-2}]}} = \sqrt{[M^2]} = [M]$
The dimension is Mass, which corresponds to Kilogram (C).
Dimension calculation:
$\sqrt{\frac{[M^{-1} L^3 T^{-2}][M L^2 T^{-1}]}{[L T^{-1}]^5}} = \sqrt{\frac{[L^5 T^{-3}]}{[L^5 T^{-5}]}} = \sqrt{[T^2]} = [T]$
The dimension is Time, which corresponds to Second (B).
Assuming 'K' represents the dimension of Kelvin ($[\Theta]$) and 'L' represents the dimension of Meter ($[L]$) within this expression:
Dimension calculation:
$\sqrt{\frac{[\Theta]^2 [L]^2 [L T^{-1}]^3}{[M^{-1} L^3 T^{-2}][M L^2 T^{-1}]}} = \sqrt{\frac{[\Theta]^2 [L]^2 [L^3 T^{-3}]}{[L^5 T^{-3}]}} = \sqrt{\frac{[\Theta]^2 [L^5 T^{-3}]}{[L^5 T^{-3}]}} = \sqrt{[\Theta]^2} = [\Theta]$
The dimension is Temperature, which corresponds to Kelvin (D).
Dimension calculation:
$\sqrt{\frac{[M^{-1} L^3 T^{-2}][M L^2 T^{-1}]}{[L T^{-1}]^3}} = \sqrt{\frac{[L^5 T^{-3}]}{[L^3 T^{-3}]}} = \sqrt{[L^2]} = [L]$
The dimension is Length, which corresponds to Meter (A).
Based on the dimensional analysis:
Therefore, the correct matching is A-IV, B-II, C-I, D-III.
A man in a car at location Q on a straight highway is moving with speed v. He decides to reach a point P in qa field at a distance d from the highway (point m) as shown in the figure. Speed of the car in the field is half to that on the highway. What should be the distance RM, so that the time taken to reach P is minimum ?

Three students $S_1$, $S_2$ and $S_3$ perform an experiment for determining the acceleration due to gravity (g) using a simple pendulum. They use different lengths of pendulum and record time for different number of oscillations. The observations are as shown in the table.

(least count of length =0.1 cm
least count for time =0.1s )
If $E_1$, $E_2$ and $E_3$ are the percentage errors in 'g' for students 1, 2 and 3 respectively, then the minimum percentage error is obtained by student no. __________.