Home
Class 10
PHYSICS
Two ends of a conducting rod of varying ...

Two ends of a conducting rod of varying cross-section are maintained at `200^(@)Cand0^(@)C` respectively. In steady state :

A

temperature differences across AB and CD are equal

B

temperature difference across AB is greater than that across CD

C

temperature difference across AB is less than that across CD

D

temperature difference may be equal or different depending upon thermal conductivity of the rod.

Text Solution

Verified by Experts

The correct Answer is:
C
Rate of flow of heat `(dQ)/(dt)` or H is equal throughout the rod,
Temperature difference is given by
`DeltaT` = (H) (Thermal Resistance)
or `DeltaTprop` Thermal Resistance R
where `R=1/(KA)orRprop1/A`
Area across CD is less. Therefore, `DeltaT` across CD will be more.
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • TRANSFER OF HEAT

    CENGAGE PHYSICS|Exercise GENERAL EXERCISE|17 Videos

  • STATIC ELECTRICITY

    CENGAGE PHYSICS|Exercise OLYMPIAD AND NTSE LEVEL EXERCISES|10 Videos

Similar Questions

Explore conceptually related problems

The temperature of the two ends A and B of a rod of length 25cm and circular cross section are 100^(@)C and 0^(@)C respectively In the steady state, find the temperature at a point 10cm from the end B (ifnore loss of heat from curved surface of the body) ?

A rod of length L and uniform cross-sectional area has varying thermal conductivity which changes linearly from 2K at end A to K at the other end B . The ends A and B of the rod are maintained at constant temperture 100^(@)C and 0^(@)C , respectively. At steady state, the graph of temperture : T=T(x) where x= distance from end A will be

Knowledge Check

  • Two ends of a conducting rod of varying cross-section are maintained at 200^(@)C and 0^(@)C respectively. In steady state:

    A
    temperature differences across `AB and CD` are equal
    B
    temperature difference aross `AB` is greater than that across `CD`
    C
    temperature difference aross `AB` is less than that across `CD`
    D
    temperature difference may be equal or different depending upon thermal conductivity of the rod.

  • Two rods of similar area of cross section and length are joined as shown in the figure. The ratio of their thermal conductivity is 2:3. The free ends are maintained at 100^(@)C and 0^(@)C respectivley. THE temperature at junction in steady state is

    A
    `50^(@)C`
    B
    `40^(@)C`
    C
    `60^(@)`
    D
    `80^(@)C`

  • Assume that the thermal conductivity of copper is twice that of aluminium and four times that of brass. Three metal rods made of copper, aluminium and brass are each 15 cm long and 2 cm in diameter. These rods are placed end to end, with aluminium between the other two. The free ends of the copper and brass rods are maintained at 100^@C and 0^@C respectively. The system is allowed to reach the steady state condition. Assume there is no loss of heat anywhere. When steady state condition is reached everywhere, which of the following statement is true?

    A
    No heat is transmitted across the copper aluminium or aluminium brass junctions.
    B
    More heat is transmitted across the copper aluminium junction than across the aluminium brass junction.
    C
    More heat is tranmitted across the aluminium brass junction than the copper aluminium junction.
    D
    Equal amount of heat is transmitted at the copper aluminium and aluminium brass junctions.

    • Similar Questions

    Explore conceptually related problems

    The ends of a copper rod of length 1m and area of cross-section 1cm^2 are maintained at 0^@C and 100^@C . At the centre of the rod there is a source of heat of power 25 W. Calculate the temperature gradient in the two halves of the rod in steady state. Thermal conductivity of copper is 400 Wm^-1 K^-1 .

    Cylinder copper rod of length 1m and a cylinder steel rod of length 1.5m are joined together end to end. The cross sectional area of eac rod is 3.14cm . The free ends of steel rod and copper rods are maintained at 0^(@)C and 100^(@)C respectively. The surfaces of rods are thermally insulated. Find the temperature of copper steel junction. (Given thermal conductivity of steel =46J//m-s.^(@)C and the thermal conductivity of copper =386J//m-s.^(@)C )

    Assume that the thermal conductivity of copper is twice that of aluminium and four times that of brass. Three metal rods made of copper, aluminium and brass are each 15 cm long and 2 cm in diameter. These rods are placed end to end, with aluminium between the other two. The free ends of the copper and brass rods are maintained at 100^@C and 0^@C respectively. The system is allowed to reach the steady state condition. Assume there is no loss of heat anywhere. Under steady state condition the equilibrium temperature of the copper aluminium junction will be

    The ends of copper rod of length 1m and area of cross section 1cm^(2) are maintained at 0^(@)C and 100^(@)C . At the centre of rod, there is a source of heat of 32W . The thermal conductivity of copper is 400W//mK

    Five rods of same material and same cross-section are joined as shown. Lengths of rods ab, ad and bc are l, 2l and 3l respectively. Ends a and c are maintained at temperatures 200^(@)C and 0^(@)C respectivelly. If x has the value calculated in the above question. Then temperature of junction b or d is

    Home
    Profile