Blood stains are found at the site of a murder: If $DNA$ profiling technique is to be used for identifying the criminal,which of the following is ideal for use?

If a complex number $z$ satisfies $|z^2-1|=|z|^2+1$,then $z$ lies on

$A$ parallel plate capacitor of area $A$,plate separation $d$ and capacitance $C$ is filled with three different dielectric materials having dielectric constants $K_1, K_2$ and $K_3$ as shown in the figure. If a single dielectric material is to be used to have the same capacitance $C$ in this capacitor,then its dielectric constant $K$ is given by: ($A =$ Area of plates)

Which of the following is not a group of cryptogams (non-flowering plants)?

$A$ wire can be broken by applying a load of $20\,kg$ weight. The force required to break the wire of twice the diameter is ......... $kg\,wt$.

Given that $a, b \in \{0, 1, 2, \ldots, 9\}$ with $a+b \neq 0$ and that $\left(a+\frac{b}{10}\right)^x = \left(\frac{a}{10}+\frac{b}{100}\right)^y = 1000$. Then,$\frac{1}{x}-\frac{1}{y}$ is equal to