Final answer:
- The total resistance in a parallel circuit is larger than the value of the largest single resistance.
- Residential loads are connected in parallel to branch circuits.
- The total load on the 120-volt circuit is 18.378 kW.
- The total load in the system with nameplate ratings is 10.1 kW.
- For three resistive loads in parallel, total resistance is the sum of individual resistances (Rt = R1+R2+R3).
- The resistance of each lamp in the low-voltage lighting system is 2.88 ohms.
This correct answer is none of the above.
Step-by-step explanation:
Certainly! Let's provide detailed explanations for each of the questions:
Characteristic of Total Resistance in a Parallel Circuit:
In a parallel circuit, the total resistance is determined by the reciprocal of the sum of the reciprocals of individual resistances. The more parallel resistances you have, the lower the total resistance.
Therefore, the total is larger than the value of the largest single resistance in the circuit.
Connection of Residential Loads and Devices to Branch Circuits:
According to the National Electrical Code, residential loads and devices such as lighting fixtures and receptacles are typically connected in parallel to branch circuits.
This allows each device to operate independently, and if one device fails or is turned off, it doesn't affect the others.
Total Load on a 120-Volt Circuit:
The total load in a parallel circuit is the sum of the individual loads. Given the currents and voltage for each load, you can use the formula P=VI to find the power for each load and then sum them up for the total power.
Total Load in a System with Namedplate Ratings:
By adding up the namedplate ratings of each load, you can determine the total load on the system. Ensure the units are consistent, and summing the power ratings will give you the total power consumed.
Statement about Three Resistive Loads Connected in Parallel:
In a parallel circuit, the total resistance is found by adding the reciprocals of the individual resistances. The correct statement is
Rt =R1 + R2 + R3, where Rt is the total resistance and R1 ,R2 ,R3 are the resistances of the individual loads.
Resistance of Each Lamp in a Low-Voltage Lighting System:
The resistance of each lamp can be calculated using Ohm's Law:
R= V2/P, where V is the voltage and P is the power. In this case, V=12 volts and P=50 watts for each lamp. Calculate R for one lamp to get the resistance.
This correct answer is none of the above.
Your correct question is: What is a characteristic of the total resistance in a parallel circuit? Select one: a. The total is equal to the sum of all the resistances. b. The total is larger than the value of the largest single resistance in the circuit. c. The total is smaller than the value of the smallest single resistance in the circuit. In general, residential loads and devices such as lighting fixtures and receptacles are connected ___ to branch circuits defined by the National Electrical Code. Select one: a. in series b. in parallel A 120-volt circuit is supplying power to three 120-volt loads. Load #1 is drawing 3.3 amps. Load #2 pulls 6.5 amps. Load #3 is drawing 5.1 amps. The total load on the circuit is ___ kW. Select one: a. 14.9 b. 1.788 c. 18.378 d. 1.531 e. 17.9 NAMEPLATE RATINGS Load 1: 2.3 KW at 240 volts Load 2: 7.8 amps at 240 volts 2-Pole CB 120/240 V 3-ph, 4-W Load #1 wuu 5240 V Load 1 Load 2 Panel LA Load #2 NEUTRAL BAR Figure 119.560 Both schematic and pictorial circuits are shown. Refer to Figure 119.560. A total load of _ kW will be used by the loads. Select one: a. 6.245 b. 4.172 c. 10.1 d. 17.383 e. 1.032 For three resistive loads that are connected in parallel, which of the following statements is the ONLY true statement? Select one: a. Total resistance is equal to the sum of the individual resistances or Rt = R1 + R2 + R3 b. Total current is equal to the sum of the individual currents through the three loads or It = 11 + 12 + 13 c. Total voltage is equal to the sum of the voltage drops across all three resistive loads or Et = E1 + E2 + E3 Figure 119.565 All lamps are type MR 16 and are rated at 50 watts when operated at 12 volts AC. An MR 16 is a type of low-voltage lamp. 12 VAC Lighting Transformer Refer to Figure 119.565. The resistance of each lamp is ___ ohms. Select one: a. 1.388 b. 11.52 C..347 d. 2.88 e. 4.17