Vegetative propagation in mint occurs by

In a biprism experiment,if the $5^{\text{th}}$ bright band with wavelength $\lambda_{1}$ coincides with the $6^{\text{th}}$ dark band with wavelength $\lambda_{2}$,then the ratio $\left(\frac{\lambda_{2}}{\lambda_{1}}\right)$ is:

Two bodies $A$ and $B$ start from the same point at the same instant and move along a straight line. $A$ moves with uniform acceleration $a$ and $B$ moves with uniform velocity $V$. They meet after time $t$. The value of $t$ is:

An $X$-ray tube is operated at $50 \ kV$. The minimum wavelength produced is ..... $\mathring{A}$.

$A$ diode having a potential difference of $0.5\,V$ across its junction,which does not depend on the current,is connected in series with a resistance of $20\,\Omega$ across a source. If $0.1\,A$ current passes through the resistance,what is the voltage of the source (in $,V$)?

If $ax^2+6xy+by^2-10x+10y-6=0$ represents a pair of perpendicular lines,then the value of $|a|$ equals