A scientist runs an electric current along a wire. A magnetic compass is placed near the wire. The scientist observes that whenever the current is turned on, the compass needle moves. Why does the compass needle move? Question 9 options: The current creates an electric field around the wire. The current creates a magnetic field around the wire. The current adds electric charge to the compass needle. The current increases the force of gravity on the compass needle.

The correct option is: The current creates a magnetic field around the wire

Explanation:

It is because the current flowing through the circuit creates a magnetic field around the wire.

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation: