Question-33 A centigrade and Fahrenheit thermometer are dipped in boiling water. The water temperature is lowered until the Fahrenheit temperature observed is 140^\circ F. At that time the temperature registered by the centigrade thermometer is
(A) 80^\circ C
(B) 60^\circ C
(C) 40^\circ C
(D) 20^\circ C
Answer : (B)
Explanation:
C = \frac{5}{9}\times (F - 32)
Substitute 140°F into the equation:
C = \frac{5}{9}\times (140 - 32)
C = \frac{5}{9}\times 108
C = 60°C
Thus, when the Fahrenheit thermometer reads 140°F, the temperature registered by the centigrade thermometer is 60°C