The angle between the lines whose direction cosines are $\left(\frac{\sqrt{3}}{4}, \frac{1}{4}, \frac{\sqrt{3}}{2}\right)$ and $\left(\frac{\sqrt{3}}{4}, \frac{1}{4}, \frac{-\sqrt{3}}{2}\right)$ is:

$A$ $p-n$ photodiode is made of a material with a band gap of $2.0 \text{ eV}$. The minimum frequency of the radiation that can be absorbed by the material is nearly

$A$ gas mixture consists of molecules of type $1, 2$ and $3$,with molar masses $m_1 > m_2 > m_3$. Let $(V_{rms})$ and $\overline{K}$ be the $r.m.s.$ speed and average kinetic energy of the gases,respectively. Which of the following is true?

$A$ steel wire can withstand a load up to $2940 ~N$. $A$ load of $150 ~kg$ is suspended from a rigid support. The maximum angle through which the wire can be displaced from the mean position, so that the wire does not break when the load passes through the position of equilibrium, is (in $^{\circ}$)

Which of the following has the largest population in a food chain?

The following figure shows a logic gate circuit with two inputs $A$ and $B$ and an output $C$. The voltage waveforms of $A$,$B$,and $C$ are as shown in the figure. The logic gate is: