Physics 2017 JAMB Past Questions - Question 20: A platinum resistance thermometer records 3.0W at 0áµ’C and 8.0W at 100áµ’C . If it records 6.0W in a certain environment , the temperature of the medium is

Correct Answer

A

Explanation

To determine the temperature of the medium when the platinum resistance thermometer records 6.0W, we can use the concept of proportionality between power and temperature.

Let's assume that the relationship between power (P) and temperature (T) is linear. We can express this relationship using the equation of a straight line:

P = mT + c

where P is the power, T is the temperature, m is the slope of the line, and c is the y-intercept.

We are given two data points: (0áµ’C, 3.0W) and (100áµ’C, 8.0W). We can use these points to find the values of m and c.

Using the first data point (0áµ’C, 3.0W):

3.0 = m(0) + c
c = 3.0

Using the second data point (100áµ’C, 8.0W):

8.0 = m(100) + 3.0
5.0 = 100m
m = 5.0/100
m = 0.05

Now that we have the values of m and c, we can substitute them into the equation to find the temperature (T) when the power (P) is 6.0W:

6.0 = 0.05T + 3.0
0.05T = 6.0 - 3.0
0.05T = 3.0
T = 3.0/0.05
T = 60áµ’C

Therefore, the temperature of the medium when the platinum resistance thermometer records 6.0W is 60áµ’C.