Variations in the resistivity of blood can give valuable clues to changes in the blood's viscosity and other properties. the resistivity is measured by applying a small potential difference and measuring the current. suppose a medical device attaches electrodes into a 1.5-mm-diameter vein at two points 5.0 {\rm cm} apart. what is the blood resistivity if a 8.9 v potential difference causes a 240 \mu a current through the blood in the vein (in omega*m)?

The resistivity is 1.31 Ωm

Explanation:

Diameter = 1.5 mm

Potential difference = 8.9 V

Current = 240 μA

length = 5.0 cm

We need to calculate the resistivity

Using ohm's law

We know that,

Formula of resistance

Put the value of R in ohm's law

Where, = resistivity

A = area

I = length

Put the value into the formula

Hence, The resistivity is 1.31 Ωm

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