Two long straight parallel wires are 2.99 m apart and carry current in the opposite directions. Wire A has 4 A and wire B has 1 A. How far from wire A is a point where the net magnetic field from the two wires is zero? Please give your answer in meters.

A concave mirror produces a virtual image that is 4 times as tall as the object. If the object is 44 cm in front of the mirror, what is the focal length of this mirror? (in units of cm)

Which one is correct looking at the image? A + C = B A + B + C = 0 B + C = A A + B = C

An object 24.0 cm from a concave mirror creates a virtual image at -33.5 cm. If the image is 7.25 cm tall, what is the height of the object? (Mind your minus signs.) (Unit = cm)

A concave mirror of focal length 17.5 cm forms a real image 24.8 cm from the mirror. What is the magnification? (Mind your minus signs.) (Unit = cm)