Advertisements
Advertisements
Question
Conceptual question.
A bird sitting on a high power electric line is still safe. How?
Advertisements
Solution
Birds don’t get shocked when they sit on electrical wires because they are not good conductors of electricity. Electricity flowing through a single power line at 35,000 volts will continue along the path of least resistance and bypass birds, because there is no difference in electrical potential.
APPEARS IN
RELATED QUESTIONS
How much work is done when one coulomb charge moves against a potential difference of 1 volt?
Keeping the resistance constant, the potential difference applied across the ends of a component is halved. By how much does the current change?
A potential difference of 20 volts is applied across the ends of a resistance of 5 ohms. What current will flow in the resistance?
A resistance of 20 ohms has a current of 2 amperes flowing in it. What potential difference is there between its ends?
Define the unit of resistance (or Define the unit "ohm").
Keeping the potential difference constant, the resistance of a circuit is doubled. By how much does the current change?
Calculate the potential difference between the two terminals of a battery if 100 joules of work is required to transfer 20 coulombs of charge from one terminal of the battery to the other.
In the figure given below, A, B and C are three ammeters. The ammeter B reads 0.5A. (All the ammeters have negligible resistance.)
Calculate:
(i) the readings in the ammeters A and C.
(ii) the total resistance of the circuit.
Two charged spherical conductors of radius R1 and R2 are connected by a wire. Then the ratio of surface charge densities of the spheres `(σ_1//σ_2 )` is ______.
