Parallel Circuits MCQs with Explanations

Understanding the Problem: We have a parallel circuit with four identical resistors. We know the total voltage across the parallel combination and the total equivalent resistance. We need to find the current flowing through each individual resistor . Key Concepts: In a parallel circuit , the voltage across each branch is the same . Ohm's Law : Voltage (V) = Current (I) x Resistance (R), or I = V/R Step-by-Step Solution: 1. Find the total current (I total ) : Using Ohm's Law for the entire circuit, I total = V total / R total = 15 V / 600 Ω = 0.025 A = 25 mA 2. Find the resistance of each resistor (R each ) : Since the resistors are in parallel and identical, the total resistance is related to the individual resistance by R total = R each / N (where N is the number of resistors). Therefore, R each = R total * N = 600 Ω * 4 = 2400 Ω 3. Find the current through each resistor (I each ) : Since the voltage across each resistor is the same as the total voltage (15 V), we can use Ohm's Law again: I each = V each / R each = 15 V / 2400 Ω = 0.00625 A = 6.25 mA Therefore, the correct answer is: Option C: 6.25 mA

First, understand what a parallel circuit means. In a parallel circuit, all the resistors are connected side-by-side to the voltage source. This means the voltage across each resistor is the same , which in this case is 110 volts. Next, we need to find the total resistance of the parallel combination. Since we have three identical resistors (47 Ω each) in parallel, we can use a simplified formula: Total Resistance (R total ) = Resistance of one resistor / Number of resistors. So, R total = 47 Ω / 3 ≈ 15.67 Ω. The total resistance is less than the resistance of any single resistor when they are in parallel. Now, we can use Ohm's Law to find the total current drawn from the source. Ohm's Law states: Current (I) = Voltage (V) / Resistance (R). Therefore, I = 110 V / 15.67 Ω ≈ 7.02 A. Looking at the options, 7.06 A (Option D) is the closest answer to our calculated value. Therefore, option D is the correct answer. Therefore, Option D: 7.06 A is the correct answer.

20 kΩ is the correct answer to “Four equal-value resistors are connected in parallel. Ten volts are applied across the parallel circuit and 2 mA are measured from the source. The value of each resistor is”. This question is standard in competitive examination syllabi for Parallel Circuits.

25 Ω is the correct answer to “Five 100 Ω resistors are connected in parallel. If one resistor is removed, the total resistance is”. This question is standard in competitive examination syllabi for Parallel Circuits.

Less than 120 Ω but greater than 100 Ω is the correct answer to “When a 1.6 kΩ resistor and a 120 Ω resistor are connected in parallel, the total resistance is”. This question is standard in competitive examination syllabi for Parallel Circuits.

True is the correct answer to “In a parallel circuit, the branch with the lowest resistance has the most current.”. This question is standard in competitive examination syllabi for Parallel Circuits.

An increase in source voltage is the correct answer to “A sudden increase in the total current into a parallel circuit may indicate”. This question is standard in competitive examination syllabi for Parallel Circuits.

490 mA is the correct answer to “There is a total of 800 mA of current into four parallel resistors. The currents through three of the resistors are 40 mA, 70 mA, and 200 mA. The current through the fourth resistor is”. This question is standard in competitive examination syllabi for Parallel Circuits.

False is the correct answer to “The total current divides among parallel resistors in a manner directly proportional to the resistance values.”. This question is standard in competitive examination syllabi for Parallel Circuits.

False is the correct answer to “Addition of resistors in parallel increases total resistance and decreases total current.”. This question is standard in competitive examination syllabi for Parallel Circuits.

False is the correct answer to “When an open circuit occurs in a parallel branch, the total resistance decreases.”. This question is standard in competitive examination syllabi for Parallel Circuits.

False is the correct answer to “The total resistance for two resistors in parallel is equal to the sum of the two resistors.”. This question is standard in competitive examination syllabi for Parallel Circuits.

5.5 Ω is the correct answer to “An ammeter has an internal resistance of 50 Ω. The meter movement itself can handle up to 1 mA. If 10 mA is applied to the meter, the shunt resistor, RSH1, is approximately”. This question is standard in competitive examination syllabi for Parallel Circuits.

12 mA is the correct answer to “In a five-branch parallel circuit, there are 12 mA of current in each branch. If one of the branches opens, the current in each of the other four branches is”. This question is standard in competitive examination syllabi for Parallel Circuits.

72 W is the correct answer to “Four 8 Ω speakers are connected in parallel to the output of an audio amplifier. If the maximum voltage to the speakers is 12 V, the amplifier must be able to deliver to the speakers”. This question is standard in competitive examination syllabi for Parallel Circuits.

R3 is open is the correct answer to “In a certain three-branch parallel circuit, R1 has 12 mA through it, R2 has 15 mA through it, and R3 has 25 mA through it. After measuring a total of 27 mA, you can say that”. This question is standard in competitive examination syllabi for Parallel Circuits.

60 Ω is the correct answer to “A 470 Ω resistor, a 220 Ω resistor, and a 100 Ω resistor are all in parallel. The total resistance is approximately”. This question is standard in competitive examination syllabi for Parallel Circuits.

True is the correct answer to “Total power in a parallel circuit is found by adding up the power of all the individual resistors.”. This question is standard in competitive examination syllabi for Parallel Circuits.

31.25 mA is the correct answer to “Four resistors are connected in parallel. Fifteen mA flows through resistor R. If the second resistor is 2R, the third resistor 3R, and the fourth resistor 4R, the total current in the circuit is”. This question is standard in competitive examination syllabi for Parallel Circuits.

1.24 A is the correct answer to “The following currents are measured in the same direction in a three-branch parallel circuit: 200 mA, 340 mA, and 700 mA. The value of the current into the junction of these branches is”. This question is standard in competitive examination syllabi for Parallel Circuits.

The remaining two will glow with the same brightness as before is the correct answer to “Three lights are connected in parallel across a 120 volt source. If one light burns out,”. This question is standard in competitive examination syllabi for Parallel Circuits.

4.8 W is the correct answer to “The power dissipation in each of four parallel branches is 1.2 W. The total power dissipation is”. This question is standard in competitive examination syllabi for Parallel Circuits.

70 mA is the correct answer to “If there are a total of 120 mA into a parallel circuit consisting of three branches, and two of the branch currents are 40 mA and 10 mA, the third branch current is”. This question is standard in competitive examination syllabi for Parallel Circuits.

True is the correct answer to “A parallel circuit acts as a current divider.”. This question is standard in competitive examination syllabi for Parallel Circuits.

True is the correct answer to “The number of current paths equals the number of resistors in parallel.”. This question is standard in competitive examination syllabi for Parallel Circuits.

7 A is the correct answer to “The currents into a junction flow along two paths. One current is 4 A and the other is 3 A. The total current out of the junction is”. This question is standard in competitive examination syllabi for Parallel Circuits.

560 Ω is the correct answer to “The following resistors are in parallel across a voltage source: 220 Ω, 470 Ω, and 560 Ω. The resistor with the least current is”. This question is standard in competitive examination syllabi for Parallel Circuits.

True is the correct answer to “Parallel resistors are connected between the same two points.”. This question is standard in competitive examination syllabi for Parallel Circuits.

Decreases is the correct answer to “When an additional resistor is connected across an existing parallel circuit, the total resistance”. This question is standard in competitive examination syllabi for Parallel Circuits.

Increases is the correct answer to “If one of the resistors in a parallel circuit is removed, the total resistance”. This question is standard in competitive examination syllabi for Parallel Circuits.

Is less than 600 Ω is the correct answer to “Six resistors are in parallel. The two lowest-value resistors are both 1.2 kΩ. The total resistance”. This question is standard in competitive examination syllabi for Parallel Circuits.

22 mA is the correct answer to “The total resistance of a parallel circuit is 50 Ω. If the total current is 120 mA, the current through the 270 Ω resistor that makes up part of the parallel circuit is approximately”. This question is standard in competitive examination syllabi for Parallel Circuits.

61 mA is the correct answer to “A set of Christmas tree lights is connected in parallel across a 110 V source. The filament of each light bulb is 1.8 kΩ. The current through each bulb is approximately”. This question is standard in competitive examination syllabi for Parallel Circuits.

1.8 A is the correct answer to “Five light bulbs are connected in parallel across 110 V. Each bulb is rated at 200 W. The current through each bulb is approximately”. This question is standard in competitive examination syllabi for Parallel Circuits.

True is the correct answer to “The sum of the currents into a junction is equal to the sum of the currents out of that junction.”. This question is standard in competitive examination syllabi for Parallel Circuits.