Physics Q27 – JEE-MAIN 2025

Home Physics Units & MeasurementsQuestion #579

In an electromagnetic system, a quantity defined as the ratio of electric dipole moment and magnetic dipole moment has dimension of

[M^{P} L^{Q} T^{R} A^{S}]

. The value of P and Q are :

Clue 1 of 3: Fundamental Dimensions

Recall the fundamental dimensions of physical quantities like charge, current, length, and time.

🧠 Full Solution Path

Step 1: Determine the dimensions of electric dipole moment✦ Active

The electric dipole moment $p$ is defined as the product of charge $q$ and distance $d$ . The dimension of charge is $[A T]$ (Ampere $\times$ Time) and the dimension of distance is $[L]$ (Length).

[p] = [q] [d] = [A T] [L] = [L A T]

Step 2: Determine the dimensions of magnetic dipole moment○ Expand

The magnetic dipole moment $M$ is defined as the product of current $I$ and area $A$ . The dimension of current is $[A]$ (Ampere) and the dimension of area is $[L^{2}]$ (Length squared).

[M] = [I] [A] = [A] [L^{2}] = [A L^{2}]

Step 3: Calculate the dimension of the ratio and identify P and Q○ Expand

The quantity in question is the ratio of electric dipole moment to magnetic dipole moment. Let's find its dimension.

Dimension of Ratio = \frac{[p]}{[M]} = \frac{[L A T]}{[A L^{2}]} = [L^{1 - 2} A^{1 - 1} T^{1}] = [L^{- 1} T^{1}]

Comparing this with the given dimension $[M^{P} L^{Q} T^{R} A^{S}]$ , we can identify the exponents:

P = 0 (since there is no M term)

Q = - 1 (from L^{- 1})

R = 1 (from T^{1})

S = 0 (since there is no A term)

The values of P and Q are $0$ and $- 1$ respectively.

✦ STEM Console utilizes AI models to generate step-by-step explanations and math clues. AI can make mistakes.

Physics Question 27 – JEE-MAIN 2025

Clue 1 of 3: Fundamental Dimensions

🧠 Full Solution Path