What order of magnitude of resistance is quoted for a metre-long piece of large-diameter copper wire?
A10^3 ohm
B10^5 ohm
C10^-2 ohm
D10^-5 ohm
Answer & Solution
Correct answer: D. 10^-5 ohm
1. Resistances of real objects spread over more than fifteen orders of magnitude.
2. Ceramic insulators used to support power lines sit at 10^12 ohm or more.
3. A dry person measures about 10^5 ohm hand to foot and the human heart about 10^3 ohm.
4. A metre of thick copper wire sits at the far other end of that range, about 10^-5 ohm.
5. That tiny value is why connecting wires in a circuit are normally treated as having negligible resistance.
6. 10^5 ohm is the human body figure, and picking it here is the usual mix-up.
_Source: OpenStax College Physics (CC BY 4.0), Ch 20 "Electric Current, Resistance, and Ohm's Law", section Resistance and Simple Circuits_
Keep practising Electric Current, Resistance, and Ohm's Law
Browse all Electric Current, Resistance, and Ohm's Law questions for B.Tech EEE, or explore more Electrical Engineering topics.
Related questions
The T wave of an electrocardiogram is generated by which event?The QRS complex of an electrocardiogram is generated by which event?In a three-electrode electrocardiogram, the lead II potential is measured between which twMultiple sclerosis arises through which mechanism?Why is no cell energy spent in the myelinated stretches of an axon?Myelin is an insulator. What does that insulation achieve for an axon?What name is given to the unmyelinated gaps that separate the myelin sheaths along an axonCompared with an unmyelinated one, how does a myelinated axon carry a nerve impulse?