JEE Main 2023 · 25 January · morning · Single correct · +4 / −1
Match List I with List II
Choose the correct answer from the options given below :
| List I | List II | ||
|---|---|---|---|
| A. | Surface tension | I. | kg m⁻¹ s⁻¹ |
| B. | Pressure | II. | kg ms⁻¹ |
| C. | Viscosity | III. | kg m⁻¹ s⁻² |
| D. | Impulse | IV. | kg s⁻² |
- (a) A-IV, B-III, C-I, D-II
- (b) A-IV, B-III, C-II, D-I
- (c) A-I, B-I, C-III, D-IV
- (d) A-III, B-IV, C-I, D-II
Answer and solution
Answer (a) A-IV, B-III, C-I, D-II
Solution
Physics sir · 3 steps
Write each one in newtons first, then expand N into kg, m and s.
- Start from force. All four quantities are built from force. In base units, 1 N = 1 kg m s⁻². Write each quantity in terms of N first, then expand.
Quantity Defined as Unit in N Base SI units List II A. Surface tension force per length N m⁻¹ kg s⁻² IV B. Pressure force per area N m⁻² kg m⁻¹ s⁻² III C. Viscosity pressure × time N s m⁻² kg m⁻¹ s⁻¹ I D. Impulse force × time N s kg m s⁻¹ II - Viscosity. From F = η A dv/dx, η = F/(A (dv/dx)). The velocity gradient has unit s⁻¹, so η is N m⁻² s = kg m⁻¹ s⁻¹.
- So. The match is A-IV, B-III, C-I, D-II, which is option (a).
The idea to keep. For mechanics units, go through force: write the quantity as N times or divided by m and s, then replace N with kg m s⁻². The power of m usually tells similar-looking units apart.
Answer from the NTA final answer key. Solution by PrepWiser.