Unlock hundreds more features
Save your Quiz to the Dashboard
View and Export Results
Use AI to Create Quizzes and Analyse Results

OR
Sign inSign in with Facebook
Sign inSign in with Google
Quizzes > Science

Ohm's Law Test: Check Your Skills in Voltage, Current, and Resistance

Quick voltage current resistance quiz with instant results and step-by-step feedback.

Editorial: Review CompletedCreated By: Milena KailenUpdated Aug 25, 2025
Difficulty: Moderate
2-5mins
Learning OutcomesCheat Sheet
Paper cutout battery resistor wire and lightning bolt on sky blue background symbolizing ohms law and electricity quiz

This Ohm's Law quiz helps you practice using V = IR to find voltage, current, and resistance in simple circuits. Work through clear questions with instant feedback, then build on it with an ohm's law quiz, a circuit basics quiz, or a current electricity quiz.

What relationship does Ohm's Law describe?
Voltage equals current times resistance
Voltage equals current divided by resistance
Resistance equals voltage times current
Power equals voltage times current
Ohm's Law states that the voltage across a resistor is directly proportional to the current flowing through it, with resistance as the constant of proportionality. This fundamental law applies to many electrical circuits under steady conditions. It forms the basis for analyzing simple resistive circuits. .
What is the SI unit of electrical resistance?
Ohm (?)
Ampere (A)
Volt (V)
Watt (W)
The SI unit for resistance is the ohm, symbolized by ?. One ohm is defined as one volt per ampere of current. This unit is named after Georg Ohm, who formulated Ohm's Law. .
What is the SI unit of electric current?
Ampere (A)
Coulomb (C)
Ohm (?)
Volt (V)
Electric current is measured in amperes, often shortened to amps (A). One ampere represents one coulomb of charge passing through a point per second. It is a fundamental unit in electrical measurements. .
What is the SI unit of electrical potential difference?
Volt (V)
Watt (W)
Ohm (?)
Ampere (A)
Voltage or electric potential difference is measured in volts (V). One volt is defined as the difference that will impart one joule of energy per coulomb of charge. It quantifies the energy change experienced by a charge in an electric field. .
In a circuit with a 12 V supply and a 4 ? resistor, what is the current?
48 A
0.33 A
16 A
3 A
Using Ohm's Law (I = V/R), the current I equals 12 V divided by 4 ?, which is 3 A. This direct calculation applies to any simple resistive circuit. It assumes ideal components and no additional sources of resistance. .
Two resistors of 2 ? and 3 ? are connected in series. What is their total resistance?
1.2 ?
0.6 ?
5 ?
6 ?
In a series circuit, resistances add directly, so R_total = 2 ? + 3 ? = 5 ?. This principle holds regardless of resistor values. Series connections increase overall resistance. .
Two 4 ? resistors are connected in parallel. What is their equivalent resistance?
1 ?
8 ?
0 ?
2 ?
For two equal resistors in parallel, R_eq = R/2, so 4 ? / 2 = 2 ?. Parallel connections reduce overall resistance. The general formula is 1/R_eq = 1/R1 + 1/R2. .
Which formula gives the electrical power dissipated by a resistor in terms of voltage and current?
P = R × I?
P = V²/R
P = V × I
P = I²/R
The general power equation is P = V × I, where V is voltage and I is current. Alternative forms like P = I²R or P = V²/R derive from Ohm's Law substitutions. Power represents the rate of energy transfer. .
A 5 ? resistor carries a current of 2 A. What is the power dissipated?
10 W
20 W
5 W
25 W
Using P = I²R, power P = (2 A)² × 5 ? = 4 × 5 = 20 W. This calculates heating or energy loss in the resistor. It's a common design check in circuits. .
If the voltage across a fixed resistor is doubled, what happens to the current through it?
It remains the same
It quadruples
It halves
It doubles
Ohm's Law (I = V/R) shows current is directly proportional to voltage when resistance is constant. Doubling V doubles I. This linear relationship holds for ohmic materials. .
Which formula relates resistance to resistivity, length, and cross-sectional area?
R = L / (? A)
R = ? A / L
R = ? L / A
R = A / (? L)
Resistance R equals resistivity ? times length L divided by cross-sectional area A (R = ?L/A). This equation shows how geometry and material affect resistance. It's crucial for designing conductors. .
What effect does increasing temperature have on the resistance of most metallic conductors?
Resistance increases
Resistance oscillates
Resistance remains constant
Resistance decreases
As temperature rises, lattice vibrations in metals increase, scattering electrons and raising resistance. This positive temperature coefficient is typical for conductors. It affects performance in power and signal circuits. .
What resistor value is indicated by the color code red - violet - yellow?
27 k?
2.7 M?
270 ?
270 k?
Color code digits: red=2, violet=7, yellow multiplier=10?, so 27 × 10? ? = 270 k?. This system is standard on 4-band resistors. Accuracy depends on tolerance band color. .
In a 10 V circuit with 2 ? and 3 ? in series, what is the voltage drop across the 3 ? resistor?
2 V
6 V
8 V
4 V
Total R = 5 ? so I = 10 V/5 ? = 2 A. Voltage drop on 3 ?: V = I×R = 2 A×3 ? = 6 V. Series circuits share current equally. .
A battery has an EMF of 12 V and internal resistance of 1 ?. What is its terminal voltage when supplying 3 A?
12 V
3 V
15 V
9 V
Terminal voltage V = EMF - I·r, so V = 12 V - (3 A×1 ?) = 9 V. Internal resistance causes a voltage drop under load. It's critical for battery performance. .
Which component exhibits a non?linear V - I characteristic and does not strictly obey Ohm's Law?
Diode
Fuse
Resistor
Wire
Diodes conduct current preferentially in one direction, showing a threshold voltage and non?linear behavior. Such devices are called non?ohmic. Ohm's Law only applies to devices with a linear V - I relationship. .
Calculate the equivalent resistance of a 30 ? resistor in series with a parallel combination of 60 ? and 120 ?.
60 ?
90 ?
70 ?
50 ?
Parallel of 60 ? and 120 ?: 1/R = 1/60 + 1/120 = 0.025 ? R = 40 ?. Series with 30 ? gives 30 + 40 = 70 ?. This two?step approach is standard. .
What is the approximate temperature coefficient of resistance for copper at room temperature?
0.039 per °C
0.0039 per °C
3.9 per °C
0.00039 per °C
Copper's temperature coefficient is about 0.0039 per °C at 20 °C. This means its resistance increases by 0.39% per degree rise. It's important for precision circuits. .
A copper wire is 2 m long with cross?sectional area 1×10?? m². Given ? = 1.68×10?? ?·m, what is its resistance?
0.00336 ?
0.0336 ?
0.0168 ?
0.168 ?
R = ?L/A = (1.68×10?? ?·m × 2 m) / 1×10?? m² = 0.0336 ?. It shows how dimensions and material affect resistance. This formula is key in conductor design. .
What complex quantity generalizes resistance in AC circuits by combining resistance and reactance?
Admittance
Conductance
Impedance
Susceptance
Impedance (Z) combines resistance (R) and reactance (X) into a complex form: Z = R + jX. It governs AC current flow similarly to resistance in DC. It's fundamental in AC circuit analysis. .
Which phenomenon causes high?frequency AC current to flow primarily near the surface of a conductor, increasing its effective resistance?
Eddy currents
Proximity effect
Skin effect
Magnetic hysteresis
The skin effect forces AC current to concentrate near a conductor's surface at high frequencies, reducing the effective cross?sectional area. This increases resistance and power loss. It's critical in RF design. .
In differential form, Ohm's Law relates current density J to the electric field E. What is the equation?
J = ? E
E = J / ?
J = E / ?
? = E × J
The microscopic form of Ohm's Law is J = ?E, where J is current density and ? is conductivity. It describes how materials respond to electric fields at the microscopic level. This relation underpins continuum electrodynamics. .
In semiconductor physics, conductivity ? often follows ? = ?? e^( - E_g/2kT). What does E_g represent?
Fermi level
Electron affinity
Bandgap energy
Ionization energy
E_g is the bandgap energy separating valence and conduction bands in a semiconductor. It determines the exponential temperature dependence of conductivity. Smaller E_g means higher intrinsic conductivity at a given T. .
Why does a four?point probe measurement eliminate the influence of contact resistance when measuring a sample's resistivity?
It uses AC instead of DC
It measures two samples simultaneously
Current and voltage are measured separately
It applies a higher test current
Four?point probes use outer contacts to inject current and inner contacts to measure voltage, so contact resistance at the current leads doesn't affect the voltage reading. This separation yields accurate sample resistivity. It's standard in thin?film characterization. .
0
{"name":"What relationship does Ohm's Law describe?", "url":"https://www.quiz-maker.com/QPREVIEW","txt":"What relationship does Ohm's Law describe?, What is the SI unit of electrical resistance?, What is the SI unit of electric current?","img":"https://www.quiz-maker.com/3012/images/ogquiz.png"}

Study Outcomes

  1. Explain Voltage-Current-Resistance Relationships -

    Describe how voltage, current, and resistance interact in electrical circuits using Ohm's Law fundamentals.

  2. Apply Ohm's Law Calculations -

    Use the ohm's law quiz problems to calculate unknown circuit values, such as voltage drops or current flow, with confidence and precision.

  3. Differentiate Series and Parallel Circuits -

    Analyze resistance in series versus parallel configurations to predict circuit behavior and solve related quiz challenges.

  4. Interpret Instant Feedback -

    Leverage the electricity quiz's real-time feedback to identify misconceptions and reinforce your understanding of electrical principles.

  5. Enhance Problem-Solving Speed -

    Develop quick and accurate strategies for tackling ohm's law questions, improving efficiency under time constraints.

  6. Evaluate Practical Circuit Scenarios -

    Apply learned concepts to realistic electrical setups, preparing you to troubleshoot and design circuits in real-world applications.

Cheat Sheet

  1. Ohm's Law Fundamentals -

    Ohm's Law, V = IR, is the cornerstone of circuit analysis. If 5 A flows through a 2 Ω resistor, the voltage drop is V = 5 × 2 = 10 V. Regularly rearranging the formula (I = V/R, R = V/I) helps sharpen problem-solving skills and builds confidence.

  2. Power and Energy in Circuits -

    Power quantifies how much work circuits perform and is given by P = VI, which can also be written as P = I²R or P = V²/R. For instance, a resistor carrying 2 A with a 10 V drop dissipates P = 10 × 2 = 20 W. Familiarizing yourself with all three forms lets you quickly choose the most convenient one for any problem.

  3. Series and Parallel Resistance -

    In a series circuit, resistances add directly (R_total = R₝ + R₂ + …), making it easy to predict voltage splits across each component. In contrast, parallel resistances follow 1/R_total = 1/R₝ + 1/R₂ + …, leading to lower overall resistance (e.g., two 100 Ω resistors in parallel give 50 Ω). Mastering these rules is crucial for analyzing complex electrical circuits and will serve you well in any ohm's law quiz.

  4. Designing Real-World Applications -

    Ohm's Law is invaluable for sizing components like resistors in LED circuits: for a 9 V source and a 2 V LED wanting 20 mA, calculate R = (9 − 2) / 0.02 = 350 Ω. This hands-on practice bridges theory and practical electrical circuits, showing you how voltage drops control current for safe, efficient designs. Incorporating such examples in your study sessions prepares you for both academic tests and lab work.

  5. Measurement Techniques and Safety -

    Accurate readings require using voltmeters in parallel and ammeters in series with your circuit; misplacing an ammeter can short out components or damage equipment. Always account for instrument internal resistance - especially in sensitive circuits - to avoid skewed results. Following safety protocols and proper meter usage will not only improve your quiz performance but also keep you and your gear protected.

Make a Quiz (FREE) Copy & Edit This Quiz Create a Quiz with AI

Physics Quizzes

Powered by: Quiz Maker