BMAT Physics Review Questions and Answers

Charge equation I=Q/t current = charge/time Resistance equation V=IR voltage = current x resistance Voltage equation (pd) V=E/Q voltage = energy/charge Power equation energy transfer P=E/t Power = energy transfer/time power voltage equation P = IV Power = current x voltage =I^2R What is energy measured in Joules What is time measured in seconds Potential difference units Watt per Amp A resistor of resistance 2.5kΩ has a voltage of 75V applied across it. What is the current through it? R = 2,500Ω V = 75V I = ? V = IR, I = V/R = 75/2500 = 3/1000 0.03A. A resistor has a potential difference of 9V applied it it for 5 minutes, while a current of 0.1A flows through it. How much energy does the resistor dissipate in that time? V = 9 V I = 0.1 A t = 300 s E = ? E = ItV = 9 x 0.1 x 300 = 270 J. If a charge of 3 MC (MegaCoulombs) is moved through a potential difference of 15GV (GigaVolts), how much energy is transferred? [Mega = 106, Giga = 109] Q = 3 x 106