Liquid cools from $50^oC$  to  $45^oC$  in  $5\  minutes$ and from $45^oC$ to $41.5^oC$ in the next $5\   minutes$.The temperature of the surrounding is ......... $^oC$
  • A$27$
  • B$40.3$
  • C$23.3$
  • D$33.3$
Easy
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
    The ends $\mathrm{Q}$ and $\mathrm{R}$ of two thin wires, $\mathrm{PQ}$ and $RS$, are soldered (joined) togetker. Initially each of the wires has a length of $1 \mathrm{~m}$ at $10^{\circ} \mathrm{C}$. Now the end $\mathrm{P}$ is maintained at $10^{\circ} \mathrm{C}$, while the end $\mathrm{S}$ is heated and maintained at $400^{\circ} \mathrm{C}$. The system is thermally insulated from its surroundings. If the thermal conductivity of wire $\mathrm{PQ}$ is twice that of the wire $RS$ and the coefficient of linear thermal expansion of $P Q$ is $1.2 \times 10^{-5} \mathrm{~K}^{-1}$, the change in length of the wire $\mathrm{PQ}$ is
    View Solution
  • 2
    Three large identical plates are kept parallel to each other. The outer two plates are maintained at temperatures $T$ and $2 T$, respectively. The temperature of the middle plate in steady state will be close to ........... $T$
    View Solution
  • 3
    Many exoplanets have been discovered by the transit method, where in one monitors, a dip in the intensity of the parent star as the exoplanet moves in front of it. The exoplanet has a radius $R$ and the parent star has radius $100 \,R$. If $I_0$ is the intensity observed on earth due to the parent star, then as the exoplanet transits
    View Solution
  • 4
    $Assertion :$ A hollow metallic closed container maintained at a uniform temperature can act as a source of black body radiation.
    $Reason :$ All metals act as black bodies.
    View Solution
  • 5
    A sphere, a cube and a disc all of the same material, quality and volume are heated to $600\,^oC$ and left in air. Which of these will have the lowest rate of cooling ?
    View Solution
  • 6
    The temperature at which a black body of unit area loses its energy at the rate of $1$ joule/second is
    View Solution
  • 7
    A black body, at a temperature of $227\,^oC$ radiates heat at a rate of $7\,cal\,cm^{-2}\, s^{-1}$ . At a temperature of $727\,^oC$ , the rate of heat radiated in the same units will be
    View Solution
  • 8
    Three rods made of the same material and having the same cross section have been joined as shown in the figure. Each rod is of the same length. The left and right ends are kept at ${0^o}C$ and ${90^o}C$ respectively. The temperature of the junction of the three rods will be ...... $^oC$
    View Solution
  • 9
    A body cools from ${50.0^o}C$ to ${49.9^o}C$ in $5\;s$. How long will it take to cool from ${40.0^o}C$ to ${39.9^o}C$? Assume the temperature of surroundings to be ${30.0^o}C$ and Newton's law of cooling to be valid ....... $\sec$
    View Solution
  • 10
    When fluids are heated from the bottom, convection currents are produced because
    View Solution