How can the rate of a reaction be increased?

(a) increasing the temperature

(b) having a lower concentration of reactants

(c) having less surface area

(d) decreasing the amount of reactants

A - Increasing the temperature.

Explanation:

Raising the reaction temperature by 10 °C can double or triple the reaction rate. This is due to an increase in the number of particles that have the minimum energy required. The reaction rate decreases with a decrease in temperature.

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .