An object is located 21.0 cm to the left of a diverging lens having a focal length f = -40.0 cm. (a) determine the location of the image. (b) determine the magnification of the image.
(c) construct a ray diagram for this arrangement.

(a). The image distance is 13.77 cm to the left side of a lens.

(b).  The magnification of the image is -0.655

Explanation:

Given that,

Object distance u= 21.0 cm

Focal length f= -40.0 cm

(a). We need to calculate the image distance

Using formula of lens

Put the value into the formula

(b). We need to calculate the magnification of the image

Using formula of magnification

Put the value into the formula

Hence, (a). The image distance is 13.77 cm to the left side of a lens.

(b).  The magnification of the image is -0.655

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia