The right atrium of the human heart receives blood from which of the following?

The image of the point $(4, -13)$ with respect to the line $5x + y + 6 = 0$ is

The angle between the tangents drawn from the point $(1,4)$ to the parabola $y^2=4x$ is

$\Delta \lambda$ is the difference between the wavelength of the $K_{\alpha}$ line and the minimum wavelength of the continuous $X$-ray spectrum when the $X$-ray tube is operated at a voltage $V$. If the operating voltage is changed to $V/3$,then the above difference is $\Delta \lambda^{\prime}$. Then:

The set $\{x \in R: \cos 2x + 2 \cos^2 x = 2\}$ is equal to

During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its absolute temperature. The ratio ${C_p}/{C_v}$ for the gas is