A constant potential difference is applied to | vedclass

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

Question

(B) In the steady state, the power dissipated by the rod is equal to the heat lost to the surroundings. Asbestos is a poor conductor of heat compared

Vedclass · Accepted Answer

In case-$1$, power lost as well as the temperature of the rod is higher.

Vedclass · Answer

(B) In the steady state, the power dissipated by the rod is equal to the heat lost to the surroundings. Asbestos is a poor conductor of heat compared to air, so the rod covered with asbestos (case-$1$) will lose heat less efficiently than the rod exposed to the atmosphere (case-$2$). Therefore, the temperature of the rod in case-$1$ will be higher. Since the resistance of the graphite rod decreases with an increase in temperature $(R \propto 1/T)$, the resistance of the rod in case-$1$ will be lower than in case-$2$. Given that the potential difference $V$ is constant, the power dissipated is given by $P = V^2/R$. Since $R$ is lower in case-$1$, the power dissipated $P$ will be higher in case-$1$.

$A$ constant potential difference is applied to the ends of a graphite rod, whose resistance decreases with a rise in temperature. The rod can be $(1)$ covered with asbestos or $(2)$ left open to the atmosphere. Answer for the steady state.

Similar Questions

$A$ wire of resistance $R$ is connected across a cell of emf $\varepsilon$ and internal resistance $r$. The current through the circuit is $I$. In time $t$,the work done by the battery to establish the current $I$ is

$A$ heater of $220\, V$ heats a volume of water in $5\, \text{min}$ time. $A$ heater of $110\, V$ heats the same volume of water in ............... $\text{min}$.

$A$ time-varying current $i$ is passed through a resistance $R$ as shown in the figure. The total heat generated in the resistance is

$n$ identical bulbs,each designed to consume power $P$ at a certain voltage source,are connected in series across the same source. The total power consumed by them is:

Two electric lamps of $40\, W$ each are connected in parallel. The power consumed by the combination will be ........... $W$.

Vedclass Test Series

Exam Paper Generator

Online Exam Module