What is the latitudinal extent of mainland India?

What do you mean by 'upper fixed point'?

Convert the following as directed. $50°\mathrm{C} \mathrm{into} °\mathrm{F}$.

What are the upper fixed points of the Celsius and the Fahrenheit scales?

Two absolute scales A and B have triple points of water defined to be $200 A$ and $350 B$. What is the relation between $T_A$ and $T_B$?

The electrical resistance in ohms of a certain thermometer varies with temperature according to the approximate law:

$R=R_o\left[1+\alpha \left(T-T_o\right)\right]$
The resistance is $101.6 \Omega$ at the triple-point of water $273.16 \mathrm{K}$, and $165.5 \Omega$ at the normal melting point of lead $600.5 K$. What is the temperature when the resistance is $123.4 \Omega$?