Basic Electricity MCQ Test!
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Welcome to the Basic Electricity MCQ Test! The three most basic components of electricity are voltage, current, and resistance. How much do you know about them and the laws of electricity that bind them together? Well, this quiz will test your knowledge about the topic. All the best!
- 1.
A 6-volt lead-acid battery has an internal resistance of 0.01 ohm. How much current will flow if the battery has a short circuit?
- A.
60A
- B.
600A
- C.
Infinite
- D.
Zero
Correct Answer
B. 600AExplanation
When a battery has a short circuit, it means that there is a direct connection between its positive and negative terminals, bypassing the internal resistance. In this case, Ohm's Law states that the current flowing through a circuit is equal to the voltage divided by the resistance. Since the internal resistance is 0.01 ohm and the voltage is 6 volts, the current flowing through the short circuit would be 6 volts divided by 0.01 ohm, which equals 600 amperes. Therefore, the correct answer is 600A.Rate this question:
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- 2.
A binary alloy of copper and zinc.
- A.
Brass
- B.
Bronze
- C.
Alnico
- D.
Steel
Correct Answer
A. BrassExplanation
Brass is a binary alloy of copper and zinc. It is a commonly used material due to its desirable properties such as high corrosion resistance, low friction, and excellent electrical conductivity. The addition of zinc to copper gives brass its distinct golden color and enhances its strength and durability. Brass is widely used in various applications, including musical instruments, plumbing fittings, decorative items, and electrical connectors.Rate this question:
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- 3.
The resistance of a conductor when its temperature is increased,
- A.
Increases
- B.
Remain constant
- C.
Varies
- D.
Decreases
Correct Answer
A. IncreasesExplanation
When the temperature of a conductor is increased, the resistance also increases. This is because as the temperature rises, the atoms in the conductor vibrate more vigorously, causing more collisions with the free electrons that carry the electric current. These collisions impede the flow of electrons, resulting in an increase in resistance. Therefore, the resistance of a conductor increases with an increase in temperature.Rate this question:
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- 4.
A voltage source of 20V is applied across the terminals of a 2.5-ohm rheostat. Calculate the powerdissipated in the rheostat?
- A.
160W
- B.
100W
- C.
150W
- D.
180W
Correct Answer
A. 160WExplanation
The power dissipated in a circuit can be calculated using the formula P = V^2 / R, where P is the power, V is the voltage, and R is the resistance. In this case, the voltage across the rheostat is 20V and the resistance is 2.5 ohms. Plugging these values into the formula, we get P = (20^2) / 2.5 = 400 / 2.5 = 160W. Therefore, the power dissipated in the rheostat is 160W.Rate this question:
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- 5.
Unit of electrical pressure is
- A.
Volt
- B.
Ohm
- C.
Ampere
- D.
Watt
Correct Answer
A. VoltExplanation
The unit of electrical pressure is volt. Volt is a measure of the electric potential difference between two points in a circuit. It represents the amount of force or pressure that pushes electric charges to flow through a conductor. The other options, ohm, ampere, and watt, are units of electrical resistance, current, and power respectively, and are not measures of electrical pressure.Rate this question:
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- 6.
Two resistors of resistances 5 ohms and 7 ohms are connected in series across a 60-volt source. What is the power absorbed in the 5-ohm resistor?
- A.
50 watts
- B.
25 watts
- C.
125 watts
- D.
100 watts
Correct Answer
C. 125 wattsExplanation
You have two resistors, one with 5 ohms of resistance and the other with 7 ohms. They are connected one after the other in a line (series) and hooked up to a 60-volt power source. Imagine electricity flowing through this setup like water through a pipe. When electricity flows through a resistor, it loses some energy and that energy turns into heat. We want to know how much heat (power) the 5-ohm resistor is making.
To figure this out, first, we need to find out how much of the 60 volts from the power source is used up by the 5-ohm resistor. We find this using a rule called the voltage divider rule, which tells us that out of the 60 volts, the 5-ohm resistor uses 25 volts. Now, we use a simple formula to find the power (heat) produced by the 5-ohm resistor. The formula is: Power (in watts) = Voltage^2 / Resistance. Plug in the values: Power = (25 volts)^2 / 5 ohms = 625 / 5 = 125 watts. So, the 5-ohm resistor is producing 125 watts of heat. That's the answer: 125 watts.Rate this question:
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- 7.
When using ohms law, E divided by I would solve for
- A.
Resistance
- B.
Voltage
- C.
Amperage
- D.
Watts
Correct Answer
A. ResistanceExplanation
When using Ohm's law, the equation E (voltage) divided by I (current) solves for resistance. Ohm's law states that the voltage across a conductor is directly proportional to the current passing through it, and the constant of proportionality is the resistance. Therefore, by dividing the voltage by the current, we can determine the resistance of the conductor.Rate this question:
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- 8.
In resistance color coding, red color is assigned to a value
- A.
1
- B.
2
- C.
3
- D.
4
Correct Answer
B. 2Explanation
In resistance color coding, the color red is assigned to the value 2.Rate this question:
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- 9.
An electric iron takes 3 ½ amps. If the heating element has a resistance of 40 ohms, what is its power consumption?
- A.
0.45 kW
- B.
0.49 kW
- C.
0.35 kW
- D.
0.51 kW
Correct Answer
B. 0.49 kW -
- 10.
Another name for a secondary cell.
- A.
Wet cell
- B.
Storage cell
- C.
Dry cell
- D.
Disposable cell
Correct Answer
B. Storage cellExplanation
A storage cell is another name for a secondary cell. Unlike disposable cells, which are designed for single use and cannot be recharged, secondary cells can be recharged and reused multiple times. Therefore, the term "storage cell" refers to a type of battery that can store and release electrical energy repeatedly.Rate this question:
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- 11.
Two resistances of 8 and 10 ohms respectively are connected in parallel and take a total current of 9 A. What is the current flowing in the 8-ohm resistance?
- A.
5 A
- B.
4 A
- C.
6A
- D.
3 A
- E.
Option 5
Correct Answer
A. 5 AExplanation
When resistances are connected in parallel, the total current is divided between them. The current flowing through each resistance is inversely proportional to their values. In this case, the resistance of 8 ohms is smaller than the resistance of 10 ohms, so it will have a larger current flowing through it. Since the total current is 9 A, the current flowing through the 8-ohm resistance can be calculated using the formula: current = total current / (total resistance / individual resistance). Plugging in the values, we get 9 A / (18 ohms / 8 ohms) = 9 A / (9/4) = 9 A * (4/9) = 4 A. Therefore, the current flowing in the 8-ohm resistance is 4 A.Rate this question:
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- 12.
What is the resistance must be connected across a 4-ohm resistor in order to give an equivalent resistance of 3 ohms?
- A.
10 ohms
- B.
12 ohms
- C.
8 ohms
- D.
None of these
- E.
Option 5
- F.
Option 6
Correct Answer
D. None of theseExplanation
In order to find the resistance that must be connected across a 4-ohm resistor to give an equivalent resistance of 3 ohms, we need to use the formula for resistors in parallel. The formula is 1/Req = 1/R1 + 1/R2, where Req is the equivalent resistance and R1 and R2 are the individual resistances. Rearranging the formula to solve for R2, we get R2 = (1/Req - 1/R1)^-1. Plugging in the given values, R1 = 4 ohms and Req = 3 ohms, we get R2 = (1/3 - 1/4)^-1 = (4/12 - 3/12)^-1 = (1/12)^-1 = 12 ohms. Therefore, the correct answer is 12 ohms.Rate this question:
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- 13.
How is voltmeter connected in a circuit?
- A.
Connect in short circuit across the load
- B.
Connect in shunt across the load
- C.
Connect in series across the load
- D.
Connect in open circuit with the load
- E.
Option 5
- F.
Option 6
Correct Answer
C. Connect in series across the loadExplanation
A voltmeter is connected in series across the load in a circuit. This means that the voltmeter is connected in such a way that it is in line with the load, allowing it to measure the voltage drop across the load. By connecting the voltmeter in series, it becomes a part of the circuit and can accurately measure the voltage without affecting the flow of current in the circuit.Rate this question:
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- 14.
Component of an atom that doesn’t have any electrical charge.
- A.
Electron
- B.
Proton
- C.
Neutron
- D.
None of these
- E.
Option 5
- F.
Option 6
Correct Answer
C. NeutronExplanation
A neutron is a component of an atom that doesn't have any electrical charge. It is located in the nucleus of the atom along with protons, which have a positive charge. Electrons, on the other hand, have a negative charge and orbit around the nucleus. Neutrons play a crucial role in determining the stability and mass of an atom.Rate this question:
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- 15.
A lead-acid cell is constructed in multiple for the purpose of ______.
- A.
Increasing the emf of the cell
- B.
Increasing the capacity of the cell
- C.
Increasing the internal resistance of the cell
- D.
All of these
- E.
Option 5
- F.
Option 6
Correct Answer
D. All of theseExplanation
A lead-acid cell is constructed in multiple for the purpose of increasing the emf of the cell, increasing the capacity of the cell, and increasing the internal resistance of the cell.Rate this question:
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- 16.
A measuring instrument used to measure the diameter of circular wires in mills.
- A.
Micrometer
- B.
Millimeter
- C.
Wire gauge
- D.
Milliammeter
Correct Answer
C. Wire gaugeExplanation
A wire gauge is a measuring instrument specifically designed to measure the diameter of circular wires in mills. It is commonly used in various industries, such as electrical and jewelry, to ensure accurate sizing and compatibility of wires. The wire gauge typically consists of a series of notches or holes with corresponding wire diameters labeled beside them. By inserting the wire into the appropriate notch or hole, the user can determine the wire's diameter. This makes the wire gauge an essential tool for measuring and selecting wires of the correct size for specific applications.Rate this question:
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- 17.
The electron in the last orbit of an atom are called
- A.
Bound electrons
- B.
Free electrons
- C.
Valence electrons
- D.
Charged electrons
Correct Answer
C. Valence electronsExplanation
Valence electrons are the electrons located in the outermost energy level or orbit of an atom. These electrons are involved in chemical reactions and determine the atom's ability to form bonds with other atoms. Bound electrons refer to all the electrons present in an atom, including both the inner and outer electrons. Free electrons are electrons that are not bound to any particular atom and are free to move within a material. Charged electrons is not a commonly used term in the context of electron location within an atom.Rate this question:
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- 18.
A 400 MCM cable has 37 strands. What is the diameter if each strand in mills?
- A.
10.81
- B.
1081
- C.
104
- D.
108
Correct Answer
C. 104Explanation
The correct answer is 104. This can be determined by dividing the total diameter of the cable (400 MCM) by the number of strands (37). This calculation gives us a result of approximately 10.81 MCM per strand. Since the question asks for the diameter in mills, we need to convert MCM to mills by multiplying by 1000. Therefore, each strand has a diameter of approximately 10,810 mills. Rounding this to the nearest whole number gives us 10,810 mills, which is equivalent to 104.Rate this question:
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- 19.
The copper field coils of a motor was measured at 21oC and found to have a resistance of 68 ohms. After the motor has run for a given time, the resistance is found to be 90 ohms. What is the hot temperature of the winding?
- A.
106.36oC
- B.
166.30oC
- C.
103.66oC
- D.
None of these
- E.
Option 5
Correct Answer
D. None of these -
- 20.
A secondary cell is charged with a constant current of 10 A for 10 hours. How much charge is accumulated?
- A.
100 coulombs
- B.
360,000 coulombs
- C.
100,000 coulombs
- D.
60,000 coulombs
Correct Answer
B. 360,000 coulombs -
- 21.
A cell whose emf is 1.45 V has an internal resistance of 4 ohms. What current will flow if this cell is connected across a 1 ohms resistor?
- A.
0.4 A
- B.
0.2 A
- C.
0.5 A
- D.
0.3 A
- E.
Option 5
- F.
Option 6
Correct Answer
D. 0.3 AExplanation
When a cell is connected to a resistor, a current flows through the circuit. The current can be calculated using Ohm's Law, which states that I = V/R, where I is the current, V is the voltage, and R is the resistance. In this case, the voltage of the cell is 1.45 V and the resistance of the circuit is 1 ohm. Plugging these values into the formula, we get I = 1.45 V / (4 ohms + 1 ohm) = 1.45 V / 5 ohms = 0.29 A, which is approximately 0.3 A. Therefore, the correct answer is 0.3 A.Rate this question:
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- 22.
What is the diameter of a copper wire having a cross sectional area of 3,969 CM?
- A.
1.6 mm
- B.
7.8 mills
- C.
0.6 inch
- D.
None of these
- E.
Option 5
- F.
Option 6
Correct Answer
D. None of these -
- 23.
Which one do When n equal resistors are connected in series to a source of emf E volts, each having a resistance of R ohms, which of the following statements is true? you like?
- A.
The voltage drop across one of the resistor is equal to E/n
- B.
The equivalent resistance of the circuit is equal to nR
- C.
The current through each of the resistor is the same
- D.
All of these
- E.
Option 5
- F.
Option 6
Correct Answer
D. All of theseExplanation
When n equal resistors are connected in series to a source of emf E volts, each having a resistance of R ohms, all of the given statements are true. The voltage drop across one of the resistors is equal to E/n, as the total voltage is divided equally among the resistors. The equivalent resistance of the circuit is equal to nR, as the resistors are connected in series. The current through each of the resistors is the same, as the current in a series circuit remains constant throughout. Therefore, the correct answer is "All of these".Rate this question:
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- 24.
A small light bulb with a resistance of 1000 ohms is connected across a 120-V line. What is the current through the bulb?
- A.
1.2 A
- B.
0.12 A
- C.
0.012 A
- D.
12 A
Correct Answer
B. 0.12 AExplanation
The current through the bulb can be calculated using Ohm's Law, which states that current (I) is equal to voltage (V) divided by resistance (R). In this case, the voltage across the bulb is 120 V and the resistance of the bulb is 1000 ohms. Therefore, the current through the bulb is 120 V / 1000 ohms = 0.12 A.Rate this question:
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- 25.
A wire whose resistance is r ohms is being cut into four equal parts. If these parts are to be connected in parallel, how much is the equivalent resistance in ohms?
- A.
R/12
- B.
R/16
- C.
R/8
- D.
R/4
- E.
Option 5
- F.
Option 6
Correct Answer
D. R/4Explanation
When the wire is cut into four equal parts and connected in parallel, the equivalent resistance can be calculated using the formula for resistors in parallel. In this case, since the wire is cut into four equal parts, each part will have a resistance of r/4 ohms. When resistors are connected in parallel, the equivalent resistance is given by the reciprocal of the sum of the reciprocals of the individual resistances. Therefore, the equivalent resistance in ohms is r/4.Rate this question:
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Jun 05, 2024Quiz Edited by
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Jan 20, 2021Quiz Created by
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