Which of the following is an si base unit for measuring length?

Meter

Explanation:

International System of Quantities is given for the seven base quantities. Meter is one of them. The meter, symbol m, is the SI unit of length. It is defined as the distance covered by the speed of light in vacuum to be 299792458.

The SI base unit that is used for measuring length is meters. Some other units are kilometers, millimeters. etc.

momentum of soft ball three times less than baskey ball

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