At constant temperature, the graph between P (pressure) vs $\frac{1}{V}$ (V=volume) of a real gas is

For an ideal gas at constant temperature (Boyle's Law, PV = constant), the graph between P and V is a hyperbola, and the graph between P and 1/V is a straight line passing through the origin. For a real gas, there are deviations from ideal behavior due to intermolecular forces and finite molecular volume. The relationship between P and V (and thus P and 1/V) is more complex than the ideal gas law. While the P vs 1/V graph for an ideal gas is a straight line, the graph for a real gas deviates from this linearity. Among the given geometric shapes, and considering the nature of deviations from ideal gas behavior, the option "hyperbola" might be considered the intended answer in some contexts, possibly by relating the deviation back to the P vs V hyperbola, although this is not a standard scientific description of the P vs 1/V graph for a real gas.