# The closed loop is located at a certain angle to the lines of magnetic induction.

**The closed loop is located at a certain angle to the lines of magnetic induction. How will the magnetic flux change if the area of the circuit decreases by 2 times, and the modulus of the magnetic induction vector increases by 4 times?**

The magnetic flux can be calculated using the formula:

Ф = B * S * cosa, where B is the modulus of the magnetic induction vector (T), S is the area bounded by the contour (m ^ 2), a is the angle between the vectors of magnetic induction and the normal to the surface.

Magnetic flux before changes:

F1 = B1 * S1 * cosa.

Magnetic flux after changes:

Ф2 = B2 * S2 * cosa.

From the initial conditions: S2 = 0.5S1; B2 = 4B1.

Change in magnetic flux:

Ф2 / Ф1 = (B2 * S2 * cosa) / (B1 * S1 * cosa) = 4B1 * 0.5S1 / (B1 * S1) = 4 * 0.5 = 2 p.

Answer. The magnetic flux will double.