Which one of the following is not a condensation polymer?

Pauling's electronegativity values for elements are useful in predicting:

Two stones of masses $m$ and $3m$ are whirled in horizontal circles,the heavier one in a radius $\left(\frac{r}{3}\right)$ and the lighter one in a radius $r$. The tangential speed of the lighter stone is '$n$' times the value of the heavier stone. When the magnitude of the centripetal force becomes equal,the value of $n$ is:

What is the equivalent capacitance of the system of capacitors between $A$ and $B$?

At a certain place,the angle of dip is $60^{\circ}$ and the horizontal component of the earth's magnetic field $(B_H)$ is $0.8 \times 10^{-4} ~T$. The earth's overall magnetic field is

All the diodes are ideal. The current flowing in the $2 \, \Omega$ resistor connected between the diodes $D_1$ and $D_2$ is .......... $A$