The $pK_a$ of a weak acid is $4.8$. What should be the ratio of $[Acid]/[Salt]$ of a buffer if $pH = 5.8$ is required?

If the amplitude of $z-2-3i$ is $\frac{\pi}{4}$,then the locus of $z=x+iy$ is:

The bond length of $HCl$ molecule is $1.275 \ \mathring{A}$ and its dipole moment is $1.03 \ D$. The ionic character of the molecule (in percent) (charge of the electron $= 4.8 \times 10^{-10} \ esu$) is

$A$ long straight wire,of radius $a$,carries a current distributed uniformly over its cross-section. The ratio of the magnetic fields due to the wire,at distance $\frac{a}{3}$ and $2a$ respectively from the axis of the wire,is

The time period of a simple pendulum is $T$. When the length is increased by $10 \ cm$,its period is $T_1$. When the length is decreased by $10 \ cm$,its period is $T_2$. Then,the relation between $T, T_1$ and $T_2$ is

The kinetic energy needed to project a body of mass $m$ from the earth's surface (radius $R$) to infinity is