A constant potential difference is applied to the ends of a graph… - Vidyadip

MCQ

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

A
in both cases power lost is same but temperature of rod is more in case- $1$
✓
in case- $1$ power lost as well as temperature of rod is more
C
in case- $2$ power lost as well as temperature of rod is more
D
in case- $1$ power lost is more but temperature of rod is less

✓

Answer

Correct option: B.

in case- $1$ power lost as well as temperature of rod is more

b
In steady state, as asbestos is a poor conductor of heat than air, temperature of rod $( 1 )$ will be higher.

Also as temperature of rod $(1)$ is high

$\Rightarrow r \downarrow \Rightarrow \frac{v^{2}}{r} \uparrow$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 10.2 , transmission of heat→10.2 , transmission of heat — all question types→Physics STD 11 Science question papers→Rajasthan Board STD 11 Science question papers→Rajasthan Board question paper generator→

Similar questions

One gram mole of an ideal gas $A$ with the ratio of constant pressure and constant volume specific heats $\gamma_{A}=5 / 3$ is mixed with $n$ gram moles of another ideal gas $B$ with $\gamma_{B}=7 / 5$. If the $\gamma$ for the mixture is $19 / 13$, then what will be the value of $n$ ?

The ranges and heights for two projectiles projected with the same initial velocity at angles $42^{\circ}$ and $48^{\circ}$ with the horizontal are ${R}_{1}, {R}_{2}$ and ${H}_{1}$, ${H}_{2}$ respectively. Choose the correct option:

If $y_1 = 5 (mm)\ \sin\pi t$ is equation of oscillation of source $S_1$ and $y_2$ $=$ $5$ $(mm)$ $sin(\pi t + \pi /6)$ be that of $S_2$ and it takes $1$ $sec$ and $\frac{1}{2}\ sec$ for the transverse waves to reach point $A$ from sources $S_1$ and $S_2$ respectively then the resulting amplitude at point $A$, is .... $mm$

The acceleration of system of two bodies over the wedge as shown in the figure is ....... $m/sec^2$

An ideal gas occupies a volume of $2\, m^3$ at a pressure of $3\times10^6\, Pa$. The energy of the gas is

At a given temperature the $r.m.s.$ velocity of molecules of the gas is

The top of insulated cylindrical container is covered by a disc having emissivity $0.6$ and thickness $1\, cm$. The temperature is maintained by circulating oil as shown in figure. If temperature of upper surface of disc is $127^o C$ and temperature of surrounding is $27^o C$, then the radiation loss to the surroundings will be (Take $\sigma = \frac{{17}}{3} \times {10^{ - 8}}W/{m^2}{K^4})$

The pointer reading v/s load graph for a spring balance is as given in the figure. The spring constant is ........ $ kg/cm$

Consider a cycle followed by an engine:

1 to 2 is isothermal.

2 to 3 is adiabatic.

3 to 1 is adiabatic.

Such a process does not exist because:

→

A drinking straw is dipped in a pan of water to depth d from the surface (see figure below). Now water is sucked into it up to an initial height $h_0$ and then left to oscillate. As a result, its height $y$ from the surface of the water varies periodically. Ignoring damping, the equation for $y$ is ( $g$ is the acceleration due to gravity):