Ohm's Law is a fundamental principle in electrical engineering and physics that describes the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit. It states that the current flowing through a conductor between two points is directly proportional to the voltage across the two points and inversely proportional to the resistance of the conductor. Mathematically, it is expressed as V = I × R, where V is the voltage in volts, I is the current in amperes, and R is the resistance in ohms. Ohm's Law is essential for analyzing electrical circuits, as it allows for the calculation of one of the three variables when the other two are known, and it applies to ohmic materials where the resistance remains constant over a range of voltages and currents.
What is Ohm's Law?
Ohm's Law states that the current (I) flowing through a conductor between two points is directly proportional to the voltage (V) across the two points and inversely proportional to the resistance (R) of the conductor, expressed as V = I × R.
What are the units of voltage, current, and resistance in Ohm's Law?
The unit of voltage is volts (V), the unit of current is amperes (A), and the unit of resistance is ohms (Ω).
If a circuit has a voltage of 12 volts and a resistance of 4 ohms, what is the current flowing through the circuit?
Using Ohm's Law, I = V / R = 12 V / 4 Ω = 3 A. Therefore, the current is 3 amperes.
What happens to the current in a circuit if the resistance is increased while the voltage remains constant?
If the resistance is increased while the voltage remains constant, the current will decrease, as they are inversely related according to Ohm's Law.
Can Ohm's Law be applied to all materials?
No, Ohm's Law applies primarily to ohmic materials, where the resistance remains constant over a range of voltages and currents. Non-ohmic materials, such as diodes and transistors, do not follow Ohm's Law.
What is the formula for Ohm's Law?
a) V = I + R
b) V = I × R
c) R = V / I
d) I = R / V
Answer: b) V = I × R
If the voltage across a resistor is 10 volts and the resistance is 5 ohms, what is the current?
a) 2 A
b) 5 A
c) 10 A
d) 15 A
Answer: a) 2 A
Which of the following materials typically obeys Ohm's Law?
a) Diodes
b) Transistors
c) Metals
d) Superconductors
Answer: c) Metals
What happens to the current in a circuit if the resistance is doubled while keeping the voltage constant?
a) The current doubles
b) The current remains the same
c) The current is halved
d) The current quadruples
Answer: c) The current is halved
What is the unit of resistance in Ohm's Law?
a) Volt
b) Ampere
c) Ohm
d) Watt
Answer: c) Ohm