Show that heat develped inn wires each of resistance r joined in paralledl between two ponts at a contant potential difference is `n^(2)` times the heat developed in the same wieres when they are joined in series beetween the same two points.

Potential difference between two points of a wire carrying 2 ampere current is 0.1 volt. Calculate the resistance between these points.

Two heater wires, made of the same material and having the same length and the same radius, are first connected in series and then in parallel to a constant potential difference. If the rate of heat produced in the two cases are Hs and Hp respectively then (Hs)/(Hp) will be

If two wires having resistance R and 2 R . Both joined in series and in parallel then ratio of heat generated in this situation, applying the same voltage,

n identical cells, each of emf E and internal resistance r, are joined in series to form a closed circuit. Find the potential difference across any one cell.

Prahar took two identical heating elements and con-nected them to a battery in two different ways as shown in the figure. When he switched ON the switch, is the heat developed in each element the same or different in both the cases ?

Two exactly similar heating resistances are connected (i) in series, and (ii) in parallel, in two different circuits, one by one. If the same current is passed through both the combinations, is more heat obtained per minute when they are connected in series or when they are connected in parallel? Give reason for you answer.

Current flowing in two wires A and B of the same length is same when the same potential difference is applied across them. If conductivity of A is n times to that of B, then calculate the ratio of radii of cross section of the two wires.

One heater coil takes time t_1 to heat a glass of water and another takes time t_2 to heat the same amount of water. How much time will it take to heat the same amount of water when the two are connected in series and when the two are connected in parallel ? voltage applied is same in all cases.