An ideal gas is undergoing a cyclic thermodynamic process in different ways as shown in the corresponding $$P-V$$ diagram in column 3 of the table. Consider only the path from state $$1$$ to state $$2.$$ $$W$$ denotes the corresponding work done on the system. The equations and plots in the table have standard notations as used in thermodynamic processes. Here $$Y$$ is the ratio of heat capacities at constant pressure and constant volume. The number of moles in the gas is $$n.$$

Which of the following options is the only correct representation of a process in which

$$\Delta U = \Delta Q - P\Delta V$$?

An ideal gas is undergoing a cyclic thermodynamic process in different ways as shown in the corresponding $$P-V$$ diagram in column 3 of the table. Consider only the path from state $$1$$ to state $$2.$$ $$W$$ denotes the corresponding work done on the system. The equations and plots in the table have standard notations as used in thermodynamic processes. Here $$Y$$ is the ratio of heat capacities at constant pressure and constant volume. The number of moles in the gas is $$n.$$

Which one of the following options correctly represents a thermodynamic process that is used as a correction in the determination of the speed of sound in an ideal gas?

A block of mass $$M$$ has a circular cut with a frictionless surface as shown. The block resets on the horizontal frictionless surface of a fixed table. Initially the right edge of the block is at $$x=0,$$ in a co-ordinate system fixed to the table. A point mass $$m$$ is released from rest at the topmost point of the path as shown and it slides down.

When the mass loses contact with the block, its position is $$x$$ and the velocity is $$v.$$ At that instant, which of the following options is/are correct?