A resistor carries a current I. The power dissipated in the resistor is P. What
ID: 1282777 • Letter: A
Question
A resistor carries a current I. The power dissipated in the resistor is P. What is the power dissipated if the same resistor carries current 3I?
A. P
B. 3P
C. 9P
D. P/9
2. Which of the following statements is false?
A. An electric field is needed to produce an electric current. B. A potential difference between two points is needed to produce an electric current. C. For a steady current to flow in a wire, the wire must be part of a closed circuit. D. The electric field is constant along all parts of the circuit when a steady current is flowing. E. The electric current in a wire is proportional to the drift velocity of the charges.Explanation / Answer
1) P = V^2/R
R = V^2/P = 30^2/20= 45 so A)
2) C) is false, just need to go to ground