Identify the point groups to which the following objects belong: (i) a sharpened cylindrical pencil, (ii) a box with a rectangular cross-section, (iii) a coffee mug with a handle, (iv) a three-bladed propeller (assume the sector-like blades are flat), (v) a three-bladed propeller (assume the blades are twisted out of the plane, all by the same amount).

The magnitude of the magnetic field at a certain distance from a long, straight conductor is represented by b. what is the magnitude of the magnetic field at twice the distance from the conductor? a. at twice the distance, the magnitude of the field is 4b.b. at twice the distance, the magnitude of the field is 2b.c. at twice the distance, the magnitude of the field is b/2.d. at twice the distance, the magnitude of the field is b/4.e. at twice the distance, the magnitude of the field remains equal to b.