Question

The temperatures of two bodies measured by a thermometer are $t_{1} = 20^{0}C \pm 0.5^{0}C$and $t_{2} = 50^{0}C \pm 0.5^{0}C$. The temperature difference and the error therein is

• A. $30^{0}C \pm 1^{o}C$
• B. $70^{0}C \pm 0.5^{o}C$
• C. $30^{0}C \pm 0.5^{o}C$
• D. $70^{0}C \pm {1^{}}^{o}C$

Answer 1

Answer: (A)

$30^{0}C \pm 1^{o}C$

Answer 2

Here,

$t_{1} = 20{^\circ}C \pm 0.5{^\circ}C$

$t_{2} = 50{^\circ}C \pm 0.5{^\circ}C$

The temperature difference of two bodies is

$t = t_{2} - t_{1} = 50{^\circ}C - 20{^\circ}C = 30{^\circ}C$

The error in temperature difference is given by

$\Delta t = (\Delta t_{1} + \Delta t_{2})$

$= (0.5{^\circ}C + 0.5{^\circ}C) = 1{^\circ}C$

$\therefore$The temperature differences is $30{^\circ}C \pm 1{^\circ}C.$