Liquid $X$ is used in a bubble chamber to detect neutral mesons and gamma photons. Then,$X$ is

For $x \in \mathbb{R}$,the range of $3 \cos (4x - 5) + 4$ lies in the interval

$A$ Zener diode,having a breakdown voltage equal to $15\, V$,is used in a voltage regulator circuit as shown in the figure. The current through the Zener diode is.....$mA$.

In a college of $300$ students,every student reads $5$ newspapers and every newspaper is read by $60$ students. The number of newspapers is:

Fluorine is more electronegative than either boron or phosphorus. What conclusion can be drawn from the fact that $BF_3$ has no dipole moment but $PF_3$ does?

$A$ rod $P$ of length $1 \ m$ is hinged at one end $A$ and there is a ring attached to the other end. Another long rod $Q$ is hinged at $B$ and it passes through the ring. The rod $P$ is rotated about an axis which is perpendicular to the plane in which both the rods are present and the variation between the angles $\theta$ and $\phi$ are plotted as shown. The distance between the hinges $A$ and $B$ is ....... $m$.