Compare the amount of heat developed in three similar wires having length in the ratio 1:5:8 and radii 1:2:3 when joined in parallel.

. Two wires of the same radius and material have their lengths in the ratio 1 : 2. If these are stretched by the same force the strain produced in the two wires will be in the ratio

Find the angle of elevation of the sun when the ratio of the length of a pillar and shadow is 1:sqrt3 .

Calculate the resistivity of a wire having resistance .02 ohm, length = 10 m and area = 1mm^2

A brass rod of length 50 cm and diameter 3.0 mm is joined to a steel rod of the same length and diameter. What is the change in length of the combined rod at 250 ^@C , if the original lengths are at 40.0 ^@C ? Is there a ‘thermal stress’ developed at the junction? The ends of the rod are free to expand (Co-efficient of linear expansion of brass = 2.0 xx 10^-5K^-1 steel = 1.2 xx 10^-5 K^-1) .

A resistance wire connected in the left gap of a metre bridge balances a 10Ω resistance in the right gap at a point which divides the bridge wire in the ratio 3:2. If the length of the resistance wire is 1.5m, then find the length of 1Ω of the resistance wire.

Find the coordinates of the point which divides the join of (-1,7) and (4,-3) in the ratio 2:3.

The length of a metal is l_1 when the tension in it is T_2 and is l_2 when the tension is T_2 . Find the original length of the wire.