Physics · Units of measurements, System of units, SI Units, fundamental and derived units
Assertion nm is not same as mN Reason
Assertion nm is not same as mN Reason \( \ln m=10^{-9} m \operatorname{and} 1 m N=10^{-3} N \)
- A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
- B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
- C. Assertion is correct but Reason is incorrect
- D. Assertion is incorrect but Reason is correct
Step-by-step solution
Assertion: nm (nanometer) is a unit of length, mN (millinewton) is a unit of force; they are physically different, so assertion is correct. Reason: correctly states that 1 nm = 10^{-9} m and 1 mN = 10^{-3} N, which are accurate conversions. However, the reason does not explain why they are not the same; it merely provides definitions without indicating they belong to different physical quantities. Hence, reason is correct but not the correct explanation for the assertion.