Which would be a common-sense practice in a lab environment?

Which configuration would produce an electric current? a) rotate a coil of copper wire between two magnets. b) connect a wire between a copper and zinc strip sitting in a beaker of water. c) connect a wire to the (+) positive end of a battery and the other end to a light bulb. d) connect a wire to the negative end of a battery and the other end to a light bulb.

Wavelength,frequency,and energy are related.what happens to a wave as it’s wavelength gets shorter?

What do we mean by the event horizon of a black hole?