The equation of the locus of $z$ such that $\left|\frac{z-i}{z+i}\right|=2$,where $z=x+iy$ is a complex number,is

An object with a mass $10 \ kg$ moves at a constant velocity of $10 \ m/s$. $A$ constant force then acts for $4 \ s$ on the object and gives it a speed of $2 \ m/s$ in the opposite direction. The impulse acting on the object is ........ $N \cdot s$.

When acetaldehyde is reacted with $LiAlH_4$,what is the product formed?

Which of the following $statement(s)$ is/are not correct?
$(i)$ Reproduction is the production of progeny possessing features dissimilar to their parents.
$(ii)$ The fungi,the filamentous algae,the protonema of mosses,all multiply by budding.
$(iii)$ Many organisms like mules,sterile worker bees do not reproduce.
$(iv)$ Reproduction is not an all-inclusive defining characteristic of living organisms.

If $\frac{2 x^3+x^2-5}{x^4-25}=\frac{A x+B}{x^2-5}+\frac{C x+1}{x^2+5}$,then $(A, B, C)$ equals to

If $f(2)=4$ and $f^{\prime}(2)=1$,then $\lim _{x \rightarrow 2} \frac{x f(2)-2 f(x)}{x-2}$ is equal to