Question

A direct current of 4 A and an alternating current of peak value 4 A flow through resistance of 3Ω and 2Ω respectively. The ratio of heat produced in the two resistances in same interval of time will be ______.

Options

• 3 : 2

• 3 : 1

• 3 : 4

• 4 : 3

Answer 1

A direct current of 4 A and an alternating current of peak value 4 A flow through resistance of 3Ω and 2Ω respectively. The ratio of heat produced in the two resistances in same interval of time will be 3 : 1.

Explanation:

As H  = `"i"_"rms"^2`Rt

H ∝ `"i"_"rms"^2`R

`"H"_1/"H"_2= (("i"_("rms"_1))/("i"_("rms"_2)))^2xx"R"_1/"R"_2`

= `(4/(4/sqrt2))^2xx3/2`

= `2xx3/2`

= `3/1`