The birds sitting on an overhead transmission line suffer no harmful effects because:
Correct answer: C. There is a negligible potential difference between their feet
- A. Their bodies have high resistance
- B. Their feet are good insulators
- C. There is a negligible potential difference between their feet
- D. Wires are insulated
Explanation
Birds perched on an overhead transmission line are not harmed because both of their feet are at the same electrical potential, eliminating the potential difference required for current to flow through their bodies. Hence, no current passes through them. Option A is incorrect because the resistance of the bird's body is not the determining factor. Option B is incorrect because the bird's feet are not insulators, but rather, they maintain the same potential on a single wire. Option D is incorrect as transmission lines are not typically insulated, but rather, the lack of potential difference keeps the birds safe.
This question appeared on the ETEA MDCAT 2012 paper, which you can sit online with every answer explained.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Steady Current
Steady current is the continuous flow of charge at a constant rate through a conductor. The topic covers current, charge, potential difference, resistance, Ohm's law, resistivity and electrical power, along with series and parallel circuits, while distinguishing conventional current direction from electron motion.
Practise Current Electricity
1,052 free Current Electricity MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Steady Current questions
Which of the following pairs have the same units and dimensions?
An electric current of 1 A is passing through a cross section of the coil in 1 second. How many electrons are involved in providing a current of 1A? The charge on 1 electron is 1.602x10 - 19 C.
The total driving force of a battery to draw current through a circuit is called:
Kirchoff's fist law (KCL) is based upon the law of conservation of:
For ohmic substance, the electron drift velocity is proportional to:
The sum of the e.m.f and potential differences around a closed circuit is zero is a consequence of: