JEE Mains · Physics · STD 11 - Units,dimensions and measurement
- JEE Mains 2023
- Medium
- MCQ
Match List\(-I\) with List\(-II\).
| List\(-I\) | List\(-II\) |
| \((A)\) Angular momentum | \((I)\) \(\left[ ML ^2 T ^{-2}\right]\) |
| \((B)\) Torque | \((II)\) \(\left[ ML ^{-2} T ^{-2}\right]\) |
| \((C)\) Stress | \((III)\) \(\left[ ML ^2 T ^{-1}\right]\) |
| \((D)\) Pressure gradient | \((IV)\) \(\left[ ML ^{-1} T ^{-2}\right]\) |
Pick an option to check your answer.
Answer & Solution
Correct Answer
(B) \((A)-(III), (B)-(I), (C)-(IV), (D)-(II)\)
Step-by-step Solution
Detailed explanation
Explanation:
Let us derive the dimensional formula for each physical quantity step-by-step to find the correct match:
1. Angular Momentum (A):
The formula for angular momentum is \( L = mvr \), where \( m \) is mass, \( v \) is velocity, and \( r \) is radius.
Dimensions: \( [M] \times [LT^{-1}] \times [L] = [ML^2T^{-1}] \)
This matches with item (III).
2. Torque (B):
The formula for torque is \( \tau = \text{Force} \times \text{perpendicular distance} \).
Dimensions: \( [MLT^{-2}] \times [L] = [ML^2T^{-2}] \)
This matches with item (I).
3. Stress (C):
The formula for stress is \( \text{Stress} = \frac{\text{Force}}{\text{Area}} \).
Dimensions: \( \frac{[MLT^{-2}]}{[L^2]} = [ML^{-1}T^{-2}] \)
This matches with item (IV).
4. Pressure Gradient (D):
The formula for pressure gradient is \( \text{Pressure gradient} = \frac{\text{Pressure}}{\text{Distance}} \).
Dimensions: \( \frac{[ML^{-1}T^{-2}]}{[L]} = [ML^{-2}T^{-2}] \)
This matches with item (II).
Combining these results, the correct matching sequence is: (A) – (III), (B) – (I), (C) – (IV), (D) – (II).
Hence, Option B is the correct choice.
Let us derive the dimensional formula for each physical quantity step-by-step to find the correct match:
1. Angular Momentum (A):
The formula for angular momentum is \( L = mvr \), where \( m \) is mass, \( v \) is velocity, and \( r \) is radius.
Dimensions: \( [M] \times [LT^{-1}] \times [L] = [ML^2T^{-1}] \)
This matches with item (III).
2. Torque (B):
The formula for torque is \( \tau = \text{Force} \times \text{perpendicular distance} \).
Dimensions: \( [MLT^{-2}] \times [L] = [ML^2T^{-2}] \)
This matches with item (I).
3. Stress (C):
The formula for stress is \( \text{Stress} = \frac{\text{Force}}{\text{Area}} \).
Dimensions: \( \frac{[MLT^{-2}]}{[L^2]} = [ML^{-1}T^{-2}] \)
This matches with item (IV).
4. Pressure Gradient (D):
The formula for pressure gradient is \( \text{Pressure gradient} = \frac{\text{Pressure}}{\text{Distance}} \).
Dimensions: \( \frac{[ML^{-1}T^{-2}]}{[L]} = [ML^{-2}T^{-2}] \)
This matches with item (II).
Combining these results, the correct matching sequence is: (A) – (III), (B) – (I), (C) – (IV), (D) – (II).
Hence, Option B is the correct choice.
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