Two heater coils made of the same material are connected in parallel across the mains : the length and the diameter of one coil is double that of the other . Which of them will produce more heat?

(a) Two heater coils made of the same material are connected in paralled across the mains. The length of diameter of one the coil is triple that of other. Which of these will produce more heat? (b) Three equal resistors connected in series across a source of emf together dissipated 10 Watt of power. What would be the power disspated if the same resistors are connected in parallel across the same source of emf? Two resistor R_(1) and R_(2) may be connect either in series or in parellel across a battery of zero internal resistance. it is required that joule heating for the parallel combination be four times than for series combination. if R_(1)= 100 Omega find R_(2) (d) The three resistance A, B and C have values 3R, 6R and R respectively. Now some potential difference is applied across the network . Find the ratio of thermal powers dissipated between X and Y . find ratio of power consumed by A,B, and C .

Two resistance wire "A" and "B" of same material are connected in parallel to the mains.The length and diameter of wire "A" are double those of wire "B" . The amounts of heat generated "Q_(A) and "Q_(B)" in "A" and "B" will be-

Two pieces of conductor of same material and of equal length are connected in series with a cell. One of the two pieces has cross-sectional area double that of the other. Which one of the following statements is correct in this regard ?

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

Two wires are of the same length, same radius, but one of them is of them is of copper and the other is of iron. Which will have more resistance ?

Two iron spheres of the same diameter are heated to the same temperature. One is soled, and the other is hollow which will expand more?

Two concentric coils carry the same current in opposite directions. The diameter of the inner coil is equal currents. The outer coil. If the magnetic field produced by the outer coil at the common centre are 1 T , the net field at the centre is

Two identical coils each of self-inductance L , are connected in series and are placed so closed to each other that all the flux from one coil links with the other. The total self-inductance of the system is

An electric kettle has tow heating coils. When one of the coils connected to an AC source, the water in the kettle boils in 10 min. when the other coil is used the water boils in 40 min. if both the coils are connected in parallel, the time taken by the same quantity of water of boil will be

Two conducting wires of the same material and of equal length and equal diameters are first connected in series and then in parallel in an electric circuit. The ratio of the heat produced in series and parallel combinations would be :