Final answer:
Using a compass near electric circuits can lead to inaccurate readings due to interference from the circuit's magnetic field. AC currents particularly cause fluctuations, while DC might have a temporary effect. Safety measures also recommend keeping one hand in your pocket to prevent electric current from passing through the heart.
Step-by-step explanation:
Importance of Using Compasses Away from Electric Circuits
When using a compass near electric circuits, there is a risk of distorting the compass readings. A traditional compass works by aligning its magnetic needle with the Earth's magnetic field, which helps in navigation and finding direction. However, when close to electric circuits, especially those involving alternating current (AC) such as that in a refrigerator, the changing magnetic fields generated by the current can interfere with the compass needle's alignment. As AC currents change direction periodically, they can cause the compass needle to fluctuate, leading to inaccurate readings. On the other hand, direct current (DC), like the one used when starting your car, produces a steady magnetic field, which may only temporarily affect the compass if there is a large surge of current.
Moreover, compasses are sensitive instruments and the presence of strong magnetic fields from electric circuits can overshadow the relatively weak Earth's magnetic field, further compromising the accuracy of the compass. In light of this, it is always advisable to use small compasses for testing magnetic fields generated by simple electric circuits like a current loop or a long straight wire which will not significantly influence the ambient magnetic field.
In addition, a safety precaution when working with high-power electric circuits is to keep one hand in your pocket to minimize the risk of an electrical current passing through the heart should an accident occur. This is because using both hands could create a path for the electrical current to travel across the chest cavity.