Why is it important to have a balanced centrifuge?

What is the energy of a photon of ultraviolet radiation with a frequency of 4.4 × 1015 hz? planck’s constant is 6.63 × 10–34

Rohit is trying to tune an instrument

Place several e-field sensors at a few points on different equipotential lines, and look at the relationship between the electric field and the equipotential lines. which statement is true? 1-at any point, the electric field is perpendicular to the equipotential line at that point, and it is directed toward lines of higher voltages. 2-at any point, the electric field is perpendicular to the equipotential line at that point, and it is directed toward lines of lower voltages. 3-at any point, the electric field is parallel to the equipotential line at that point.