object of size 7.0 cm is placed at 27 CM in front of a concave mirror of focal length 18 cm at what distance from the mirror should a screen be placed so that a shaft forecast image can be obtained find the size and the nature of the image

what are the options.

explanation:

wire in brush may conduct electricity from cell to drill and vice versa electrc shock possible

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

e/c, where e is its total energy