Two rods of same material have same length an | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) The heat flow is given by $\Delta Q = \frac{\Delta T}{R_{eq}} t$,where $\Delta T$ is the temperature difference and $R_{eq}$ is the equivalent the

Vedclass · Accepted Answer

$3$

Vedclass · Answer

(B) The heat flow is given by $\Delta Q = \frac{\Delta T}{R_{eq}} t$,where $\Delta T$ is the temperature difference and $R_{eq}$ is the equivalent thermal resistance.For two identical rods of resistance $R$,the series resistance is $R_{series} = R + R = 2R$.For the series case,$\Delta Q = \frac{\Delta T}{2R} 	imes 12$.When joined in parallel,the equivalent resistance is $R_{parallel} = \frac{R 	imes R}{R + R} = \frac{R}{2}$.For the parallel case,$\Delta Q = \frac{\Delta T}{R/2} 	imes t$.Equating the two expressions for $\Delta Q$: $\frac{\Delta T}{2R} 	imes 12 = \frac{\Delta T}{R/2} 	imes t$.$\frac{12}{2R} = \frac{2t}{R} \Rightarrow 6 = 2t \Rightarrow t = 3 \, 	ext{minutes}$.

Two rods of same material have same length and area. The heat $\Delta Q$ flows through them for $12 \, \text{minutes}$ when they are joined in series. If now both the rods are joined in parallel,then the same amount of heat $\Delta Q$ will flow in ........ $\text{minutes}$.

Similar Questions

The angle between the lines whose direction cosines satisfy the equations $l + m + n = 0$ and $l^2 = m^2 + n^2$ is

$\int \frac{x-1}{(x+1) \sqrt{x(x^2+x+1)}} dx = $

Which of the following bonds is the most polar?

Which of the following reactions is correct?

$Assertion$ : The driver in a vehicle moving with a constant speed on a straight road is in a non-inertial frame of reference.
$Reason$ : $A$ reference frame in which Newton's laws of motion are applicable is non-inertial.

Vedclass Test Series

Exam Paper Generator

Online Exam Module