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

Consider a system to be two train cars traveling toward each other. what is the total momentum of the system before the train cars collide?   kg • what must the total momentum of the system be after the train cars collide?   kg •  

Current from a charged capacitor lights a bulb. as time goes on the brightness of the

An electron in an x-ray machine is accelerated through a potential difference of 1.00 × 104 v before it hits the target. what is the kinetic energy of the electron in electron volts?