Which of the following components of an electrical circuit is a source of voltage?
a. a switch
b. a battery
c. a resistor
d. a light bulb

Which of these statements is true? a. quarks pair with leptons to form protons and neutrons. b. quarks pair with bosons to form photons. c. quarks pair with photons to form protons and neutrons. d. quarks pair with other quarks to form protons and neutrons. e. quarks pair with electrons to form protons.

Efficiency is the ratio of to for a system a)power in to power in b)power in to power out c) power out to power out d) power out to power in

Which body is in equilibrium? (1) a satellite orbiting earth in a circular orbit (2) a ball falling freely toward the surface of earth (3) a car moving with a constant speed along a straight, level road (4) a projectile at the highest point in its trajectory