The recessive genes located on the $X$-chromosome in humans are always:

The mass of a spaceship is $1000\,kg$. It is to be launched from the earth's surface out into free space. The values of $g$ and $R$ (radius of earth) are $10\,m/s^2$ and $6400\,km$ respectively. The required energy for this work will be:

If $X$ is a Poisson variate such that $P(X=1)=2 P(X=2)$, then $P(X=3)$ is equal to

The work function of a substance is $4.0 \, eV$. The longest wavelength of light that can cause photoelectron emission from this substance is approximately ............ $nm$.

The function $f: R \rightarrow R$ is defined by $f(x) = \cos^2 x + \sin^4 x$ for $x \in R$. Then the range $f(R)$ is equal to

The equation of the circle which passes through the origin and cuts orthogonally each of the circles $x^2+y^2-6x+8=0$ and $x^2+y^2-2x-2y-7=0$ is