The resistance of the wire in the platinum resistance thermometer at ice point is 5 Ω and at steam point is 5.25 Ω . When the thermometer is inserted in an unknown hot bath its resistance is found to be 5.5 Ω . The temperature of the hot bath is

Question

The resistance of the wire in the platinum resistance thermometer at ice point is 5 Ω and at steam point is 5.25 Ω . When the thermometer is inserted in an unknown hot bath its resistance is found to be 5.5 Ω . The temperature of the hot bath is (A)  100°C  (B)  200°C  (C)  300°C  (D)  350°C

Tardigrade Admin · Accepted Answer

For resistance thermometers t=(Rt-R0/R100-R0)×100°C Here Rt=5.5 Ω, R0=5 Ω, R100=5.25 Ω ∴ t=(5.5-5/5.25-5)×100 =(0.5/0.25)×100 =200° C

Q. The resistance of the wire in the platinum resistance thermometer at ice point is $5 Ω$ and at steam point is $5.25 Ω$ . When the thermometer is inserted in an unknown hot bath its resistance is found to be $5.5 Ω$ . The temperature of the hot bath is

$10 0^{\circ} C$

$20 0^{\circ} C$

$30 0^{\circ} C$

$35 0^{\circ} C$

For resistance thermometers
$t = \frac{R _{t} - R _{0}}{R _{100} - R _{0}} \times 10 0^{\circ} C$
Here $R_{t} = 5.5Ω, R_{0} = 5Ω, R_{100} = 5.25Ω$
$∴ t = \frac{5.5 - 5}{5.25 - 5} \times 100$
$= \frac{0.5}{0.25} \times 100$
$= 20 0^{\circ} C$

Q. The resistance of the wire in the platinum resistance thermometer at ice point is 5Ω and at steam point is 5.25Ω . When the thermometer is inserted in an unknown hot bath its resistance is found to be 5.5Ω . The temperature of the hot bath is

100∘C

200∘C

300∘C

350∘C