\begin{aligned}
&\text { A point source of light is used in an experiment of photo-electric effects. If the distance between the source and the } \\
&\text { photo-electric surface is doubled, which of the following may result? } \\
&\text { (A) Stopping potential will be halved } \\
&\text { (B) photo-electric current will decrease } \\
&\text { (C) Maximum kinetic energy if photo-electrons will decrease } \\
&\text { (D) Stopping potential will increase slightly } \\
&\text { }
\end{aligned}
