The three resistance of equal value are arranged in the different combinations shown below. Arrange them in increasing order of power dissipation.
A.
$$III < II < IV < I$$
B.
$$II < III < IV < I$$
C.
$$I < IV < III < II$$
D.
$$I < III < II < IV$$
Answer :
$$III < II < IV < I$$
Solution :
III < II < IV < I.
Power dissipation, $${P_1} = {I^2}\left( {3R} \right) = 3{I^2}R$$
Power dissipation, $${P_2} = {I^2}\left( {\frac{{2R}}{3}} \right) = 0.67{I^2}R$$
Power dissipation, $${P_3} = {I^2}\left( {\frac{R}{3}} \right) = 0.33{I^2}R$$
Power dissipation, $${P_4} = {I^2}\left( {\frac{3}{2}R} \right) = 1.5{I^2}R$$
Releted MCQ Question on Electrostatics and Magnetism >> Electric Current
Releted Question 1
The temperature coefficient of resistance of a wire is 0.00125 per $$^ \circ C$$ At $$300\,K,$$ its resistance is $$1\,ohm.$$ This resistance of the wire will be $$2\,ohm$$ at.
The electrostatic field due to a point charge depends on the distance $$r$$ as $$\frac{1}{{{r^2}}}.$$ Indicate which of the following quantities shows same dependence on $$r.$$
A.
Intensity of light from a point source.
B.
Electrostatic potential due to a point charge.
C.
Electrostatic potential at a distance r from the centre of a charged metallic sphere. Given $$r$$ < radius of the sphere.