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The current formula is derived from Ohm's law. Current is defined as the flow of electrons in an electric circuit. The flow of electrons occurs due to potential differences. The current is also known as the rate of change of charge with time. Current is represented by I and SI unit of current is Ampere. Let us learn the application of the electric current formula in the section below.
What Is the Current Formula?
Ohm's Law states that the voltage (V) across a conductor is equal to the product of the current (I) flowing through it and the resistance (R) of the conductor. According to Ohm's law, the current is the ratio of the potential difference (voltage) and the resistance. Thus, the electric current formula is given by: I = V/R
- I represent current in Ampere (A),
- V is the potential difference in Volt (V)
- R is the resistance in Ohm (Ω).
This current equation can be used to calculate the current in a circuit if the voltage and resistance are known, or to calculate the current or resistance if the other two values are known.
Let us see the applications of the current formula in the following solved examples section.
Examples Using Current Formula
Example 1: In an electric circuit, the potential difference and the resistance are given as 20V and 4Ω respectively. Calculate current flowing in the circuit.
To find: Current (I) flowing in the circuit.
V = 20 V, R = 4 Ω
Using current equation,
I = V/R
I = 20/4
I = 5
Answer: Current flowing in the circuit is 5 Ampere.
Example 2: The total current flowing in an electric circuit is 50 Amp whereas the resistance of the wires is 14 Ohm. Find the potential difference.
To find the potential difference:
I = 50 A, R = 14 Ω
Using electric current formula
I = V/R
50 = V/14
V = 50 × 14
V = 700
Answer: Potential difference is 700 V.
Example 3: In an electric circuit, the potential difference is 20 V and the value of current is 5 Amp respectively. Using the current formula, find the resistance of the circuit.
To find the resistance (R) of the circuit:
V = 20 V, I = 5 Amp
Using current formula
R = V/I
R = 20/5
R = 4 Ω
Answer: The resistance of the circuit 4 Ω.
FAQs on Current Formula
How Do You Calculate Current Using Current Formula?
If the voltage (V) and resistance (R) of any circuit is given we can use the electric current formula to calculate the current, i.e., I = V/R (amps).
How Do You Calculate Voltage Using Current Formula?
If the current (I) and resistance (R) of any circuit is given we can mold the current formula to calculate the voltage, i.e., V = IR (Volts).
Can the Current Formula be Used for Both DC and AC Circuits?
The current equation (I = V/R) is used for both direct current (DC) and alternating current (AC) circuits. However, it's important to note that for AC circuits, the resistance (R) is often replaced by impedance (Z) since AC circuits involve the effects of both reactance and resistance.
How Do You Calculate Resistance Using the Current Formula?
If the current (I) and potential difference (V) of any circuit are given we can mould the current formula to calculate the resistance, i.e., R = V/I (Ohms Ω).
What Is the Definition of Electric Current Formula? Write Its SI Unit.
The current is the ratio of the potential difference and the resistance. It is represented as (I). The current formula is given as I = V/R. The SI unit of current is Ampere (Amp).
What Happens if the Resistance is Zero in the Current Formula?
The current equation is I = V/R. If the resistance, R = 0, I = V/R would result in an undefined value for current (I/0). In practical terms, it means when an extremely high current can flow, potentially causing damage to the circuit or equipment, i.e., it would imply a short circuit.