Q151 / 160 · WBJEE 2011 · Physics
Two temperature scales \(\mathrm{A}\) and \(\mathrm{B}\) are related by \(\frac{\mathrm{A}-42}{110}=\frac{\mathrm{B}-72}{220}\). At which temperature two scales have the same reading ?
- A\(-42^0\)
- B\(-72^0\)
- Correct answerC\(+12^0\)
- D\(-40^{\circ}\)
Solution
Hints: \(\frac{\mathrm{A}-42}{110}=\frac{\mathrm{B}-72}{220}, \mathrm{~A}=\mathrm{B}\)
\(\frac{A-42}{110}=\frac{A-72}{220}\)
\(\begin{aligned}
& 2 \mathrm{A}-84=\mathrm{A}-72 \\
& \mathrm{~A}=12
\end{aligned}\)
Hence, the correct answer is option: 'C'.