Question
Four separate resistors are shown with a potential difference across them. Rank in order, from largest to smallest, the power dissipated in resistors (1) to (4). 1, 2, 3, 4 4, 2, 3, 1 4, 2, 1, 3 2, 4, 1, 3 2, 4, 3, 1 A waterbed heater uses 450 W of power. If the heater is on for an entire day, how much will it cost at a rate of $0.11/kWh? $1.19 $1190 $49.50 $0.79 $0.12 A flat iron is marked "120 V, 600 W". In normal use, the current in it is: 2 A 4 A 5 A 7.2 A 0.2 A Three resistors connected in series have individual voltages labeled delta V_1, delta V_2 and delta V_3, respectively. Which of the following expresses the value of the total voltage delta V_T taken over the three resistors together? delta V_T = delta V_1 + delta V_2 + delta V_3 delta V_T = (1/delta V_1 + 1/delta V_2 + 1/delta V_3) delta V_T = delta V_1 = delta V_2 = delta V_3 delta V_T = (1/delta V_1 + 1/delta V_2 + 1/delta V_3)^1 delta V_T = (delta V_1 + delta V_2 + delta V_3)/3 Resistances of 2.0 ohm, 4.0 ohm, and 6.0 ohm and a 24 V battery are all in series. The current in the 2.0 ohm resistor is: 0.5 A 2.0 A 2.4 A 4.0 A 12 A "The sum of the currents into a junction equals the sum of the currents out of the junction" is a consequence of: Conservation of charge Conservation of energy Newton's second law Newton's third law Ohm's law Each of the resistors in the diagram is 12 ohm. The resistance of the entire circuit is: 5.8 ohm 25 ohm 48 ohm 120 ohm none of these
Explanation / Answer
We know that,
Power = potential diffrence * Current applied,
also we know
Current,I = V/R,
so
power = V2/R
therefore,
in 1 P=V2/R
in 2 P= 4V2/R
in 3 P = V2/2R, and
in 4 P = 2V2/R
therefore correct order will be 2>4>1>3
