A copper bar has dimensions of 2.0 cm $\times$ 3.0 cm $\times$ 5.0 cm. To get the largest resistance for the bar when it is used as a resistor, we should attach the leads to the two opposite sides that have the dimensions
A) 2.0 cm $\times$ 5.0 cm.
B) 3.0 cm $\times$ 5.0 cm.
C) 2.0 cm $\times$ 3.0 cm.
D) any of the above; the resistance of the bar would be the same.

Question

Quizplus · Accepted Answer

Resistance is highest when the length through which current has to travel is the longest and the cross-sectional area through which it travels is the smallest. Attaching leads to the sides measuring 2.0 cm $\times$ 3.0 cm means current travels the 5.0 cm length, maximizing resistance.

A Copper Bar Has Dimensions of 2 ×\times× 30 Cm ×\times× 50 Cm to Get the Largest Resistance for the Bar When

A Copper Bar Has Dimensions of 2 $\times$ 30 Cm $\times$ 50 Cm to Get the Largest Resistance for the Bar When