Author Question: A rectangular loop of wire carrying a 4.0-A current is placed in a magnetic field of 0.60 T. The ... (Read 134 times)

Wadzanai · **on:** Jul 29, 2018

A rectangular loop of wire carrying a 4.0-A current is placed in a magnetic field of 0.60 T. The magnitude of the torque acting on this wire when the plane of the loop makes a 30 angle with the field is measured to be 1.1 N m.

What is the area of this loop? A) 0.20 m2
B) 0.40 m2
C) 0.26 m2
D) 0.80 m2
E) 0.53 m2

Question 2

The focal length of the lens of a simple film camera is 40.0 mm.

By what amount should the distance between the lens and the film be increased or decreased to change the focus from a person who is 25 m from the lens to one who is 4.0 m from the lens?
A) 0.2 mm
B) 0.3 mm
C) 0.4 mm
D) 0.5 mm
E) 0.7 mm