# Emissivity of a body is equal to absorptive if the body is

1.  In thermal equilibrium

2.  At low temperature

3.  At high temperature

4.  None of these

4

In thermal equilibrium

Explanation :
No Explanation available for this question

# Emissivity of a body is equal to absorptive for radiation

1.  With equal wavelength and temperature

3.  In infrared range

4.  All of these

4

With equal wavelength and temperature

Explanation :
No Explanation available for this question

# In grey body emissivity is

1.  Less than 1

2.  Equal to 1

3.  More than 1

4.  None of these

4

Less than 1

Explanation :
No Explanation available for this question

# A body whose absorptive does not vary with temperature and wave length of the incident ray, is known as

1.  Black body

2.  White body

3.  Grey body

4.  Opaque body

4

Grey body

Explanation :
No Explanation available for this question

# Absorptive of all bodies must lie between

1.  0 and 0.1

2.  -1 and +1

3.  0 and 1.0

4.  None of these

4

0 and 1.0

Explanation :
No Explanation available for this question

# Absorptive and reflectivity of a white body respectively are

1.  0 and 0

2.  1and 0

3.  0 and 1

4.  1 and 1

4

0 and 1

Explanation :
No Explanation available for this question

# Absorptive and reflectivity of black body respectively are

1.  0 and 0

2.  1and 0

3.  0 and 1

4.  1 and 1

4

1and 0

Explanation :
No Explanation available for this question

# Absorptive and reflectivity of transparent body respectively are

1.  0 and 0

2.  1and 0

3.  0 and 1

4.  1 and 1

4

0 and 0

Explanation :
No Explanation available for this question

# Wave length for maximum emissive power is given by

1.  Weans law

2.  Stefan’s law

3.  Kirchhoff’s law

4.  Planck’s law

4

Weans law

Explanation :
No Explanation available for this question

# Relation between the emissive and absorptive power of a body is given by

1.  Weans law

2.  Stefan’s law

3.  Kirchhoff’s law

4.  Planck’s law

4