An aluminum rod of length 3.14m is of square cross-section `3.14times3.14mm^(2)` .What should be the radius of 1m long another rod of same material to have equal resistance?

A wire of given metarial having length l and ares of cross-section A has a resistance of 4 Omega . What would be the resistance of another wire of the same meterial having length l/2 and area of cross-section 2A ?

A fuse with a circular cross - sectional radius of 0.15 mm blows at 15 A . What should be the radius of the cross section of a fuse made of the same material that blows at 30 A ?

A cylindrical conductor of length l and uniform area of cross-section A has resistance R . Another conductor of length 2 l and resistance R of the same material has area of cross-section :

Find the thermal resistance of an aluminium rod of length 20cm and area of cross section 1cm^(2) . The heat current is along the length of the rod. Thermal conductivity of aluminium =200Wm^(-1)K^(-1) .

A stress of 10^(6) N//m^(2) is required for breaking a material. If the density of the material is 3 xx 10^(3) Kg//m^(3) , then what should be the minimum length of the wire made of the same material so that it breaks by its own weight (g = 10m//s^(2))

A light rod of length 2 m is suspended from ceiling horizontally by means of two vertical wires of equal length tied to its ends. One of the wires is made of steel and is of cross-section 0.1 cm sq. and the other of brass of cross-section 0.2 cm sq. Along the rod at what distance a weight may be hung to produce equal stresses in the wires? (Y_("Steel") = 2 xx 10^(11) Nm^(-2), Y_("Bass") = 1 xx 10^(11) Nm^(-2))

A copper rod of length 20cm and cross-sectional area 2mm^(2) is joined with a similar aluminium rod as shown in figure .Find the resistance of the combination between the ends, Resistivity of copper =1.7xx10^(-8)(Omega)m and that of aluminium =2.6xx10^(-8)(Omega)m .

A metal rod of the length 10cm and a rectangular cross-section of 1 cm x 1//2 cm is connected to a battery across opposite faces. The resistance will be

When a rod of length 2.5 m and radius 10 mm is subjected to a force the elongation is 3mm and decrease of radius is 0.0025 mm. Find poisson.s ratio of the material of the rod.

A composite rod is made by joining a copper rod, end to end, with a second rod of different material but of the same area of cross section. At 25^(@)C , the composite rod is 1 m long and the copper rod is 30 cm long. At 125^(@)C the length of the composite rod increases by 1.91 mm . When the composite rod is prevented from expanding by holding it between two rigid walls, it is found that the constituent rods have remained unchanged in length inspite of rise of temperature. Find young's modulus and the coefficient of linear expansion of the second rod (Y of copper =1.3xx10^(10) N//m^(2) and a of copper =17xx10^(-6)//K ).