Which of the following options represent the variation of photoelectric current with property of light shown on the x-axis?

A pipe open at both ends has a fundamental frequency $f$ in air. The pipe is now dipped vertically in a water drum to half of its length. The fundamental frequency of the air column is now equal to:

Two identical point masses $P$ and $Q$, suspended from two separate massless springs of spring constants $k_1$ and $k_2$, respectively, oscillate vertically. If their maximum speeds are the same, the ratio ( $A Q / A_\rho$ ) of the amplitude $A Q$ of mass $Q$ to the amplitude $A_\rho$ of mass $P$ is

The output ( $Y$ ) of the given logic implementation is similar to the output of an/a ________ gate.