The graph between two temperature scales A and B is shown in the figure. Between upper fixed and lower fixed points, there are 150 equal divisions on scale A and 100 on scale B. The relationship for conversion between the two scales is given by 

                                     

1. tA-180100=tB150

2. tA-30150=tB100


3. tB-180150=tA100


4. tB-40100=tA180

(2) Hint: Use the concept of conversion of scales.
Step 1: Find the lowest and highest points of the scales.
It is clear from the graph that the lowest point for scale A is 30° and the lowest point for scale B 0°. The highest point for scale A is 180° and for scale, B is 100°.
Step 2: Use the conversion formula.
Hence, the correct relation is:
tA-(LFP)A(UFP)A-(LFP)A=tB-(LFP)B(UFP)B-(LFP)B
              
              tA-30180-30=tB-0100-0
               tA-30150=tB100
where LFP  Lower fixed point
           UFP Upper fixed point