A slab of insulating material of thickness 6 cm and thermal conductivity 1.4kJ/m hr deg is placed between and is in contact with two parallel electrodes, and is then subjected to high frequency dielectric heating at a uniform rate of 140,000kJ/m3 hr. At steady state coefficients of combined radiation and convection are 42 and 48 kJ/m2 hr deg. If atmospheric temperature is 25 degree Celsius, find surface temperatures?

165.40 degree Celsius and 165.45 degree Celsius

144.10 degree Celsius and 134.47 degree Celsius

123.50 degree Celsius and 154.34 degree Celsius

121.60 degree Celsius and 115.45 degree Celsius

165.40 degree Celsius and 165.45 degree Celsius

The given expression can be used to solve the electrode temperature t w1 and t w2q g δ = h 1 α 1 + h 2 α 2Where, α 1 = A (t w 2 – t a) and α 2 = (t w1 – t a).

and α 2 = (t w1 – t a).a) True

What maximum thickness of concrete can be poured without causing the temperature gradient to exceed 98.5 degree Celsius per meter anywhere in the slab? Consider a 1.2 m thick slab of poured concrete (k = 1.148 W/m degree) with both of side surfaces maintained at a temperature of 20 degree Celsius. During its curing, chemical energy is released at the rate of 80 W/m3. Workout the maximum temperature of concrete

with both of side surfaces maintained at a temperature of 20 degree Celsius. During its curing, chemical energy is released at the rate of 80 W/m3. Workout the maximum temperature of concretea) 2.64 mb) 3.64 mc) 4.64 md) 5.64 m

A composite slab consists of 5 cm thick layer of steel (k = 146 kJ/m hr degree) on the left side and a 6 cm thick layer of brass (k = 276 kJ/m hr degree) on the right hand side. The outer surfaces of the steel and brass are maintained at 100 degree Celsius and 50 degree Celsius. The contact between the two slabs is perfect and heat is generated at the rate of 4.2 * 10 5 k J/m2 hr at the plane of contact. The heat thus generated is dissipated from both sides of composite slab for steady state conditions. Calculate the temperature at the interface

on the left side and a 6 cm thick layer of brass (k = 276 kJ/m hr degree) on the right hand side. The outer surfaces of the steel and brass are maintained at 100 degree Celsius and 50 degree Celsius. The contact between the two slabs is perfect and heat is generated at the rate of 4.2 * 10 5 k J/m2 hr at the plane of contact. The heat thus generated is dissipated from both sides of composite slab for steady state conditions. Calculate the temperature at the interfacea) 115.26 degree celsiusb) 125.26 degree celsiusc) 135.26 degree celsiusd) 145.26 degree celsius

Consider a 1.2 m thick slab of poured concrete (k = 1.148 W/m degree) with both of side surfaces maintained at a temperature of 20 degree Celsius. During its curing, chemical energy is released at the rate of 80 W/m3. Workout the maximum temperature of concrete

with both of side surfaces maintained at a temperature of 20 degree Celsius. During its curing, chemical energy is released at the rate of 80 W/m3. Workout the maximum temperature of concretea) 30.73 degree celsiusb) 29.73 degree celsiusc) 28.73 degree celsiusd) 27.73 degree celsius

THE_GIVEN_EXPRESSION_CAN_BE_USED_TO_SOLVE_THE_ELECTRODE_TEMPERATURE_T_W1_AND_T_W2?$

and ‚âà√≠¬¨¬± 2 = (t w1 ‚Äö√Ñ√∂‚àö√ë‚àö¬® t a).

A slab of insulating material of thickness 6 cm and thermal conductivity 1.4kJ/m hr deg is placed between and is in contact with two parallel electrodes, and is then subjected to high frequency dielectric heating at a uniform rate of 140,000kJ/m3 hr. At steady state coefficients of combined radiation and convection are 42 and 48 kJ/m2 hr deg. If atmospheric temperature is 25 degree Celsius, find surface temperatures?$

165.40 degree Celsius and 165.45 degree Celsius

144.10 degree Celsius and 134.47 degree Celsius

123.50 degree Celsius and 154.34 degree Celsius

121.60 degree Celsius and 115.45 degree Celsius

165.40 degree Celsius and 165.45 degree Celsius

15 + Mcqs in Dielectric Heating in Heat Transfer Page 1 McqOptions

1.	A slab of insulating material of thickness 6 cm and thermal conductivity 1.4kJ/m hr deg is placed between and is in contact with two parallel electrodes, and is then subjected to high frequency dielectric heating at a uniform rate of 140,000kJ/m3 hr. At steady state coefficients of combined radiation and convection are 42 and 48 kJ/m2 hr deg. If atmospheric temperature is 25 degree Celsius, find surface temperatures?
A.	144.10 degree Celsius and 134.47 degree Celsius
B.	123.50 degree Celsius and 154.34 degree Celsius
C.	121.60 degree Celsius and 115.45 degree Celsius
D.	165.40 degree Celsius and 165.45 degree Celsius
Answer» D. 165.40 degree Celsius and 165.45 degree Celsius

2.	The given expression can be used to solve the electrode temperature t w1 and t w2q g δ = h 1 α 1 + h 2 α 2Where, α 1 = A (t w 2 – t a) and α 2 = (t w1 – t a).
A.	and α 2 = (t w1 – t a).a) True
B.	False
Answer» C.

3.	Dielectric heating apparatus consists of
A.	4 electrodes
B.	Elemental strip
C.	No Insulating material
D.	4 plates
Answer» C. No Insulating material

4.	What maximum thickness of concrete can be poured without causing the temperature gradient to exceed 98.5 degree Celsius per meter anywhere in the slab? Consider a 1.2 m thick slab of poured concrete (k = 1.148 W/m degree) with both of side surfaces maintained at a temperature of 20 degree Celsius. During its curing, chemical energy is released at the rate of 80 W/m3. Workout the maximum temperature of concrete
A.	2.64 m
B.	3.64 m
C.	4.64 m
D.	5.64 m
E.	with both of side surfaces maintained at a temperature of 20 degree Celsius. During its curing, chemical energy is released at the rate of 80 W/m3. Workout the maximum temperature of concretea) 2.64 mb) 3.64 mc) 4.64 md) 5.64 m
Answer» C. 4.64 m

5.	A composite slab consists of 5 cm thick layer of steel (k = 146 kJ/m hr degree) on the left side and a 6 cm thick layer of brass (k = 276 kJ/m hr degree) on the right hand side. The outer surfaces of the steel and brass are maintained at 100 degree Celsius and 50 degree Celsius. The contact between the two slabs is perfect and heat is generated at the rate of 4.2 * 10 5 k J/m2 hr at the plane of contact. The heat thus generated is dissipated from both sides of composite slab for steady state conditions. Calculate the temperature at the interface
A.	115.26 degree celsius
B.	125.26 degree celsius
C.	135.26 degree celsius
D.	145.26 degree celsius
E.	on the left side and a 6 cm thick layer of brass (k = 276 kJ/m hr degree) on the right hand side. The outer surfaces of the steel and brass are maintained at 100 degree Celsius and 50 degree Celsius. The contact between the two slabs is perfect and heat is generated at the rate of 4.2 * 10 5 k J/m2 hr at the plane of contact. The heat thus generated is dissipated from both sides of composite slab for steady state conditions. Calculate the temperature at the interfacea) 115.26 degree celsiusb) 125.26 degree celsiusc) 135.26 degree celsiusd) 145.26 degree celsius
Answer» C. 135.26 degree celsius

6.	Consider a 1.2 m thick slab of poured concrete (k = 1.148 W/m degree) with both of side surfaces maintained at a temperature of 20 degree Celsius. During its curing, chemical energy is released at the rate of 80 W/m3. Workout the maximum temperature of concrete
A.	30.73 degree celsius
B.	29.73 degree celsius
C.	28.73 degree celsius
D.	27.73 degree celsius
E.	with both of side surfaces maintained at a temperature of 20 degree Celsius. During its curing, chemical energy is released at the rate of 80 W/m3. Workout the maximum temperature of concretea) 30.73 degree celsiusb) 29.73 degree celsiusc) 28.73 degree celsiusd) 27.73 degree celsius
Answer» C. 28.73 degree celsius

7.	THE_GIVEN_EXPRESSION_CAN_BE_USED_TO_SOLVE_THE_ELECTRODE_TEMPERATURE_T__{W1_}AND_T__W2?$
A.
B.	and ‚âà√≠¬¨¬± <sub>2</sub> = (t <sub>w1 </sub>‚Äö√Ñ√∂‚àö√ë‚àö¬® t <sub>a</sub>).
C.	True
Answer» C. True

9.	Dielectric heating apparatus consists o?
A.	4 electrodes
B.	Elemental strip
C.	No Insulating material
D.	4 plates
Answer» C. No Insulating material

11.	Unit of specific resistance is
A.	Ohm mm<sup>2</sup>/m
B.	Ohm mm
C.	Ohm/m
D.	Ohm mm/m
Answer» B. Ohm mm

12.	The insulating material used in dielectric heating is
A.	Coal
B.	Silver
C.	Coin
D.	Wool
Answer» E.

14.	Generally heat generated depends on some parameters. It is directly proportional to
A.	Time
B.	Conductivity
C.	Voltage
D.	Distance between plates
Answer» D. Distance between plates

15.	Which one of the following materials are quickly heated by applying high frequency?
A.	Textiles
B.	Engines
C.	Rubber
D.	Coal
Answer» B. Engines

Explore topic-wise MCQs in Heat Transfer.

The given expression can be used to solve the electrode temperature t w1 and t w2q g δ = h 1 α 1 + h 2 α 2Where, α 1 = A (t w 2 – t a) and α 2 = (t w1 – t a).

Dielectric heating apparatus consists of

Consider a 1.2 m thick slab of poured concrete (k = 1.148 W/m degree) with both of side surfaces maintained at a temperature of 20 degree Celsius. During its curing, chemical energy is released at the rate of 80 W/m3. Workout the maximum temperature of concrete

THE_GIVEN_EXPRESSION_CAN_BE_USED_TO_SOLVE_THE_ELECTRODE_TEMPERATURE_T_W1_AND_T_W2?$

Dielectric heating apparatus consists o?

Unit of specific resistance is

The insulating material used in dielectric heating is

Consider a 1.2 m thick slab of poured concrete (k = 1.148 W/m degree) with both of side surfaces maintained at a temperature of 20 degree Celsius. During its curing, chemical energy is released at the rate of 80 W/m3. Workout the maximum temperature of concrete

Generally heat generated depends on some parameters. It is directly proportional to

Which one of the following materials are quickly heated by applying high frequency?

THE_GIVEN_EXPRESSION_CAN_BE_USED_TO_SOLVE_THE_ELECTRODE_TEMPERATURE_T__{W1_}AND_T__W2?$

Consider a 1.2 m thick slab of poured concrete (k = 1.148 W/m degree) with both of side surfaces maintained at a temperature of 20 degree Celsius. During its curing, chemical energy is released at the rate of 80 W/m³. Workout the maximum temperature of concrete