CONDUCTION WILL INCREASE 4. CONVECTION WILL INCREASE OF THESE STATE...

3. Conduction will increase

4. Convection will increase

Of

these

statements:

(a) 1, 2 and 3 are correct

(b) 1, 2 and 4 are correct

(c) 1, 3 and 4 are correct

(d) 2, 3 and 4 are correct

IES-37. A cube at high temperature is immersed in a constant temperature

bath. It loses heat from its top, bottom and side surfaces with heat

transfer coefficient of h

1

, h

2

and h

3

respectively. The average heat

transfer coefficient for the cube is:

[IES-1996]

1

1

1

(a)

h

1

+

h

3

+

h

3

(b)

(

h h h

1

3

3

 

)

1/3

(c)

h

+

h

+

h

(d) None of the above

1

2

3

IES-38. Assertion (A): When heat is transferred from a cylinder in cross flow to

an air stream, the local heat transfer coefficient at the forward

stagnation point is large.

[IES-1995]

Reason (R): Due to separation of the boundary layer eddies

continuously sweep the surface close to the forward stagnation point.

(a) Both A and R are individually true and R is the correct explanation of A

(b) Both A and R are individually true but R is not the correct explanation of A

(c) A is true but R is false

(d) A is false but R is true

IES-39. Match List-I (Flow pattern) with List-II (Situation) and select the

correct answer using the codes given below the lists:

[IES-1995]

Page 48 of 97

List-I List-II