A bare roof of a warmly heated home on a snowy day indicates

When you leave your warm house for an hour or so on a cold day, to save energy you should turn the thermostat

A galvanometer calibrated to read current is

Wood is a poor conductor

If a light signal and a radio signal were emitted simultaneously from the Moon, the first signal to reach Earth would be

Which requires more energy?

When the tiny hole in a pinhole camera is made larger, the image is

A positive and a negative charge near each other are released. As they move, the force on each particle

An electronic game requires 6 V for operation. With a transformer it can be powered by a 120-V outlet. If the primary has 500 turns, the secondary has

A 340-Hz sound wave travels at 340 m/s in air with a wavelength of