Introduction:
When a current passes through a circular loop, a magnetic field is generated around the loop. This phenomenon is described by Ampere's law and the right-hand rule. Understanding the magnetic field due to a current through a circular loop is crucial in many applications such as electromagnets and electric motors.

Magnetic Field Direction:
The direction of the magnetic field around a current-carrying circular loop can be determined using the right-hand rule. If we imagine holding the loop with our right hand, such that our thumb points in the direction of the current, the curled fingers will indicate the direction of the magnetic field. The field lines form concentric circles around the loop.

Magnetic Field Strength:
The strength of the magnetic field due to a current through a circular loop can be calculated using the formula:

B = (μ₀ * I * R²) / (2 * R³)

where B represents the magnetic field strength, μ₀ is the permeability of free space (a constant value), I is the current flowing through the loop, and R is the radius of the loop.

Effects of Changing Parameters:
Changing the current through the loop will directly affect the strength of the magnetic field. As the current increases, the magnetic field strength also increases.

Similarly, altering the radius of the loop will impact the magnetic field strength. Increasing the radius will result in a stronger magnetic field, while decreasing the radius will weaken the field.

Conclusion:
When a current passes through a circular loop, a magnetic field is generated around the loop. The direction of the magnetic field can be determined using the right-hand rule. The strength of the magnetic field depends on the current flowing through the loop and the radius of the loop. Understanding the magnetic field due to a current through a circular loop is essential in various applications in physics and engineering.