# university physics

posted by .

A platinum resistance thermometer has resistances of 200.0 ohms when placed
in a 0 degrees Celsius ice bath and 253.8 ohms when immersed in a crucible contacting melting potassium. What is the
melting point of potassium? Hint: First determine the resistance of the platinum resistance
thermometer at room temperature, 20 degrees Celsius.

• university physics -

for Pt α =0.00392 (1/℃).

R₁=R₀[1+α(T₁-T₀)]
R₂= R₀[1+α(T₂-T₀)]

R₁/R₂=[1+α(T₁-T₀)]/[1+α(T₂-T₀)]
200/253.8=(1- 0.00392 •20)/[1+ 0.00392• (T₂-20)]
Solving for T₂ gives
T₂=63.2℃

## Similar Questions

1. ### Algebra 2

two resistors are connected in parallel. Their resistances are 6 ohms and 10 ohms. What is the resistance, (R), of the combination?
2. ### Algebra 2

two resistors are connected in parallel. Their resistances are 8 ohms and 17 ohms. What is the resistance (R) of the combination?
3. ### physics

The resistances of a platinum resistance thermometer at the ice point, the steam point and the boiling point of sulphur are 2.50,3.50,and 6.50 respectively. find the boling point of sulphur on the platinum scale. the ice point and …
4. ### physics

The resistance of a platinum resistance thermometer is 30 ohms at the ice point, 40 ohms at the steam point and 34.5 ohms on a certain hot day, what is the temperature of the day on celcius temperature day?
5. ### physics

The resistance of a platinum resistance thermometer is 30 ohms at the ice point, 40 ohms at the steam point and 34.5 ohms on a certain hot day, what is the temperature of the day on celcius temperature day?
6. ### physics

Pls help me with this, The resistance of a platinum resistance thermometer is 30 ohms at the ice point, 40 ohms at the steam point and 34.5 ohms on a certain hot day, what is the temperature of the day on celcius temperature day?
7. ### chemistry

Say you have two substances, A and B. A has a melting point of 300 degrees Celcius, while B has a melting point of 200 degrees Celcius. If you took a mixed melting point where the ratio of A is higher than B, what would the melting …
8. ### physics

the resistance of a platinum resistance thermometer is 200.0 ohm at o degree centigrade and 257.6 ohm when immersed in hot bath,what is the temperature of the bath when 'alpha' for platinum is 0.00392degree centigrade inverse.
9. ### PHYSICS

A certain resistance thermometer at triple point of water is 152.0 ohms. What is the temperature of the system in degrees celsius when the resistance of the thermometer is 230.51ohms.
10. ### physics

A faulty Celsius thermometer read 0.7degrees Celsius at melting point of pure ice and 99.5degrees Celsius at boiling point of water at normal pressure. What is the correct temperature when it reads 30 degrees Celsius

More Similar Questions