1. What light phenomena results in a spectrum of colors that escapes when two reflections
happened inside the water droplets?

A. A primary rainbow
C. A supernumerary bow
B. A secondary rainbow
D. A Halo

2. The reason why Hertz used the same length of wire from CA to CB.
I. The voltage reached at the same direction,
II. The voltage reached at the same point.
III. The voltage reached at the same time.

A. I only
C. ll and Ill only
B. I and Il only
D. lll only
be

3. Hertz's observation on his experiment.
I. When sparks flew across the main gap, sparks flew across the secondary
gap.
II. When sparks flew across the main gap, sparks stopped across the
secondary gap.
III. When sparks flew across the main gap, secondary gap do not ignite.

A. I only
C. II and III only
B. I, II and III
D. III only​