If a line makes an angle of $$\pi /4$$ with the positive directions of each of $$x$$-axis and $$y$$-axis, then the angle that the line makes with the positive direction of the $$z$$-axis is :

If $$\widehat u$$ and $$\widehat v$$ are unit vectors and $$\theta $$ is the acute angle between them, then $$2\widehat u \times 3\widehat v$$ is a unit vector for :

Which of the following transitions in hydrogen atoms emit photons of highest frequency ?

If in a $$p$$-$$n$$ junction diode, a square input signal of $$10$$ $$V$$ is applied as shown

Then the output signal across $${R_L}$$ will be