Question

Three resistances of equal values are arranged in four different configurations as shown below. Power dissipation in the increasing order is

• A. $( III ) < ( II ) < ( IV ) < ( I )$
• B. $( II ) < ( III ) < ( IV ) < ( I )$
• C. $(I) < ( IV ) < ( III ) < ( II )$
• D. $( I ) < ( III ) < ( II ) < ( IV )$

Answer 1

Answer: (A)

For figure I,
Total resistance $=3 R $
I power $=I^{2}(3 R)$
For figure II,
Resistance $=\frac{2 R}{3} \Omega $
II power $=I^{2}\left(\frac{2 R}{3}\right)$
For figure III,
Total resistance $=\frac{R}{3} \Omega $
III power $=I^{2}\left(\frac{R}{3}\right)$
For figure IV,
Total resistance $\frac{3}{2} \Omega$
IV power $=I^{2}\left(\frac{3}{2} R\right)$