What is the size of $Wolffia$ $globosa$?

Equation of one of the tangents passing through $(2,8)$ to the hyperbola $5 x^2-y^2=5$ is

If $z = \frac{y}{x} \left[ \sin \frac{x}{y} + \cos \left( 1 + \frac{y}{x} \right) \right]$,then $x \frac{\partial z}{\partial x}$ is equal to

Due to the Doppler effect,the shift in wavelength observed is $0.1 \ \mathring{A}$ for a star producing a wavelength of $6000 \ \mathring{A}$. The velocity of recession of the star will be ...... $km/s$.

If $A, B$ and $C$ are any three sets,then $A - (B \cup C)$ is equal to

If $\lambda_0$ is the de-Broglie wavelength for a proton accelerated through a potential difference of $100 \ V$,the de-Broglie wavelength for an $\alpha$-particle accelerated through the same potential difference is