Which among the following is a haloalkyne?

The point at which the circles $x^2+y^2-4x-4y+7=0$ and $x^2+y^2-12x-10y+45=0$ touch each other is:

When a glass prism of refracting angle $60^{\circ}$ is immersed in a liquid,its angle of minimum deviation is $30^{\circ}$. The critical angle of glass with respect to the liquid medium is (in $^{\circ}$)

If $f(x) = x^3 - 6x^2 + 9x + 3$ is a decreasing function,then $x$ lies in

$A$ centigrade and a Fahrenheit thermometer are dipped in boiling water. The water temperature is lowered until the Fahrenheit thermometer registers $140^{\circ}F$. What is the fall in temperature as registered by the centigrade thermometer in $^{\circ}C$?

The heat energy absorbed by a system undergoing the cyclic process shown in the figure is: