Maximum density of $H_2O$ is at the temperature .......... $^\circ F$.

The graph between two temperature scales $P$ and $Q$ is shown in the figure. Between the upper fixed point and the lower fixed point,there are $150$ equal divisions on scale $P$ and $100$ divisions on scale $Q$. The relationship for conversion between the two scales is given by:

On a linear temperature scale $Y$,water freezes at $-160^{\circ}Y$ and boils at $-50^{\circ}Y$. On this $Y$ scale,a temperature of $340\,K$ would be read as........ $^{\circ}Y$ (water freezes at $273\,K$ and boils at $373\,K$).

Assertion $(A)$: Rapidly changing temperatures can be measured by thermocouples.
Reason $(R)$: The thermal capacity of the junction of a thermocouple is very small.

The graph $AB$ shown in the figure is a plot of the temperature of a body in degree Celsius $(C)$ versus degree Fahrenheit $(F)$. Then:

The temperature on a Fahrenheit temperature scale that is twice the temperature on a Celsius temperature scale is: (in $^{\circ} F$)