Question

If value of surface tension of a liquid is 70 dyne/cm, then its value in N/m will be

• A. \(7\times 10^{3}\mathrm{N/m}\)
• B. \(7\times 10^{2}\mathrm{N/m}\)
• C. \(7\times 10^{-2}\mathrm{N/m}\)
• D. \(70\mathrm{N/m}\)

Hint:

To convert dyne/cm to N/m, multiply by \(10^{-3}\).

Answer 1

The Correct Option is C

To convert the surface tension value from dyne/cm to N/m, we need to understand the unit conversion between these systems. Here's the step-by-step explanation:

1. The given surface tension of the liquid is 70 dyne/cm.
2. We know that \(1 \, \text{N} = 10^5 \, \text{dyne}\) and \(1 \, \text{m} = 100 \, \text{cm}\).
3. To convert dyne/cm to N/m, we use the conversion factor:
4. Convert 70 dyne/cm to N/m using the formula:

\(70 \, \text{dyne/cm} \times \left(\frac{1 \, \text{N}}{10^5 \, \text{dyne}}\right) \times \left(\frac{100 \, \text{cm}}{1 \, \text{m}}\right) = 70 \times 10^{-3} \, \text{N/m}\)

1. Simplifying the above calculation gives:
2. Thus, the correct converted value of surface tension is \(7 \times 10^{-2} \, \text{N/m}\).

Therefore, the correct answer is \(7 \times 10^{-2} \, \text{N/m}\).