# The process of heat transfer from a hot body to a cold body in a straight line, without affecting the intervening medium, is known as

1.  Conduction

2.  Convection

4.  All of these

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Explanation :
No Explanation available for this question

# Transfer of heat by molecular collision is known is

1.  Conduction

2.  Convection

4.  All of these

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Conduction

Explanation :
No Explanation available for this question

# Basic law of heat conduction is

1.  Fourier’s law

2.  Newton’s law

3.  Stefan’s law

4.  First law of thermodynamics

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Fourier’s law

Explanation :
No Explanation available for this question

# Assumption made in the Fourier’s law is that the heat flow

2.  Through a solid is one dimensional

3.  Both (a) and (b)

4.  None of these

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Both (a) and (b)

Explanation :
No Explanation available for this question

# Metals are good heat conductors because

1.  Of free electrons present

2.  Their atoms are relatively far apart

3.  Their atoms collide frequently

4.  All of these

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Their atoms collide frequently

Explanation :
No Explanation available for this question

# If thermal conductivity of a material of wall varies as K0 (1 + αt), then the temperature at the centre of the wall as compared to that in case of constant thermal conductivity, will be

1.  More

2.  Less

3.  Same

4.  Depend on other factors

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More

Explanation :
No Explanation available for this question

# With increase in temperature, thermal conductivity of solid metals

1.  Increases

2.  Decreases

3.  Remains same

4.  Depend on other factors

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Depend on other factors

Explanation :
No Explanation available for this question

# Highest thermal conductivity is of

1.  Solid ice

2.  Melting ice

3.  Water

4.  Steam

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Solid ice

Explanation :
No Explanation available for this question

# Rate of heat conduction through a thick sphere (Q) of radii r1 and r2 is equal to

1.  4 ρk (t1 – t2)/ (r2 – r1)

2.  4 ρk (r1r2)/ (r2 – r1)

3.  4 ρk (r1r2) (t1 – t2)/ (r2 – r1)

4.  None of these

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4 ρk (r1r2) (t1 – t2)/ (r2 – r1)

Explanation :
No Explanation available for this question

1.  (r1+ r2)/2

2.  √(r1 r2)

3.  r1 r2

4.  (r1 r2)/2

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