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.
  • Ain both cases power lost is same but temperature of rod is more in case- $1$
  • Bin case- $1$ power lost as well as temperature of rod is more
  • Cin case- $2$ power lost as well as temperature of rod is more
  • Din case- $1$ power lost is more but temperature of rod is less
Medium
art

Download our app
and get started for free

Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*

Similar Questions

  • 1
    Following graph shows the correct variation in intensity of heat radiations by black body and frequency at a fixed temperature
    View Solution
  • 2
    One likes to sit under sunshine in winter season, because
    View Solution
  • 3
    Steel wire of length ' $L$ ' at $40^{\circ} C$ is suspended from the ceiling and then a mass ' $m$ ' is hung from its free end. The wire is cooled down from $40^{\circ} C$ to $30^{\circ} C$ to regain its original length ' $L$ '. The coefficient of linear thermal expansion of the steel is $10^{-5} /{ }^{\circ} C$, Young's modulus of steel is $10^{11} N / m ^2$ and radius of the wire is $1 \ mm$. Assume that $L \gg$ diameter of the wire. Then the value of ' $m$ ' in $kg$ is nearly
    View Solution
  • 4
    The radiation energy density per unit wavelength at a temperature $T$ has a maximum at a wavelength $\lambda _0$. At temperature $2T$, it will have a maximum at a wavelength
    View Solution
  • 5
    Which of the following statements is true/correct
    View Solution
  • 6
    A black body at $1227^o C$ emits radiations with maximum intensity at a wavelength of $5000\;\mathring A$ . If the temperature of the body is increased by $1000^o C$, the maximum intensity will be observed at ...... $\mathring A$
    View Solution
  • 7
    Find effective thermal resistance between $A$ & $B$ of cube made up of $12$ rods of same dimensions and shown given thermal conductivity. [ $l =$ length of rod, $a =$ cross section area of rod]
    View Solution
  • 8
    The temperature of a liquid drops from $365K$ to $361 K$ in $2$ minutes. Find the time during which temperature of the liquid drops from $344\;K$ to $342K$. Temperature of room is $293\;K$  ....... $\sec$
    View Solution
  • 9
    Two spheres of the same material have radii $1\  m$ and $4\  m$ and temperatures $4000\  K$ and $2000\  K$ respectively. The ratio of the energy radiated per second by the first sphere to that by the second is
    View Solution
  • 10
    In an experment ot verify Newton's law of cooling, a graph is plotted between, the temperature difference $(\Delta T )$ of the water and surroundings and time as shown in figure. The initial temperature of water is taken as $80^{\circ} \,C$. The value of $t _{2}$ as mentioned in the graph will be...........
    View Solution