Two wires of copper are of the same length but have different diameters. When they are connected in series across a battery, the heat generated is H1, when connected in parallel across the same battery, the heat generated during the same time is H2 Then :

Explanation

When two wires of the same material and length are connected in series, their total resistance increases, which leads to a decrease in the current flowing through the circuit according to Ohm's Law (V = IR). As a result, the heat generated (H) is given by the equation H = I2Rt. In parallel, the effective resistance decreases, allowing more current to flow and therefore more heat to be produced over the same time period. Thus, we conclude that H1 (heat generated in series) is less than H2 (heat generated in parallel), making option B the correct answer. Other options are incorrect as they do not accurately reflect the relationships between current, resistance, and heat generation in different circuit configurations.