At a distance of 5.1 cm from a long straight wire carrying current/ the magnetic field is 2.5 mT. A 1.0 cm diameter loop carries the same current/ as the long straight wire. What is the strength of the magnetic field at the center of the loop? 78 μT 79 μT 80 μT 78 mT 79 mT 80 mT none of the above
![A circular loop has radius R and carries current I2 in a clockwise direction. The center of the loop is a distance D above a long, straight wire. a) What is the direction of the current I1 in the wire if the net magnetic field at the center of the loop is zero? [1 mark] b) Derive an equation for the magnitude of the current I1 [5 marks]](https://www.doubtrix.com/uploads/editor/2052784266aURCnjCQic.png)
