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Multiple choice physics transfer of heat applications of heat conduction applications of insulation clothes - our necessity

What will be the conductivity of pure silicon crystal at 300 K temperature if  electron cottoer pair at this temperature is $ 1.072 \times 10^{10} /cm^3 $ and $ \mu _n = 1350 cn^2 /V-s and \mu _p = 480 cm^2/ V-s $ ?

  1. $ 3.14 \times 10^{-4} mho /cm $
  2. $ 3.14 \times 10^{-5} mho /cm $
  3. $ 3.14 \times 10^{-6} mho /cm $
  4. $ 3.14 \times 10^{3} mho /cm $
Reveal answer Fill a bubble to check yourself
C Correct answer
Multiple choice physics transfer of heat applications of heat conduction applications of insulation clothes - our necessity

The heat capacity of a body depends on 

  1. the heat given

  2. the temperature rasied

  3. the mass of the body

  4. the material of he body.

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Heat capacity (C) is defined as the amount of heat required to raise the temperature of a body by one degree. It is given by C = m * c, where m is the mass and c is the specific heat capacity of the material.

Multiple choice physics transfer of heat applications of heat conduction applications of insulation clothes - our necessity

In a steady state of thermal conduction, temperature of the ends $A$ and $B$ of a $20cm$ long rod are $100^oC$ and $0^oC$, respectively. What will be the temperature of the rod at a distance of $6cm$ from the end $A$ of the rod?

  1. $-30^oC$
  2. $70^oC$
  3. $5^oC$
  4. None of the above

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In steady state, the temperature gradient is linear. Temperature T(x) = T_A - (T_A - T_B) * (x / L). T(6) = 100 - (100 - 0) * (6 / 20) = 100 - 100 * 0.3 = 100 - 30 = 70 degrees Celsius.