Which relation is wrong?

Question

Accepted Answer

1. **Analyze Option A:** 1 calorie is defined as the heat energy required to raise the temperature of 1 g of water by $1^{\circ}$C. The mechanical equivalent of heat is approximately $4.18$ J (or $4.186$ J). Thus, $1 	ext{ Cal} \approx 4.18 	ext{ J}$. This relation is correct .
2. **Analyze Option B:** The Angstrom ($\mathring{A}$) is a unit of length used in atomic physics. $1 \mathring{A} = 10^{-10} 	ext{ m}$. This relation is correct .
3. **Analyze Option C:** 1 electron volt (eV) is $1.6 	imes 10^{-19}$ J. Therefore, 1 Mega electron volt (MeV) = $10^6 	ext{ eV} = 10^6 	imes (1.6 	imes 10^{-19} 	ext{ J}) = 1.6 	imes 10^{-13} 	ext{ J}$. This relation is correct .
4. **Analyze Option D:** The Newton (N) is the SI unit of force, and the Dyne is the CGS unit of force. 
   - $1 	ext{ N} = 1 	ext{ kg m s}^{-2} = (1000 	ext{ g})(100 	ext{ cm}) 	ext{ s}^{-2} = 10^5 	ext{ g cm s}^{-2} = 10^5 	ext{ Dynes}$.
   - The option states $1 	ext{ N} = 10^{-5} 	ext{ Dynes}$, which is incorrect. The correct relation is $1 	ext{ Dyne} = 10^{-5} 	ext{ N}$ .

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