MCQOPTIONS
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MCQOPTIONS
This section includes 341 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Process Calculation knowledge and support exam preparation. Choose a topic below to get started.
| 301. |
Energy strikes a vertical hemispherical plate with an intensity of 640 W/m². The absorptivity is thrice the transmissivity and twice the reflectivity. Determine the rate of absorption |
| A. | 449.12 W/m² |
| B. | 349.12 W/m² |
| C. | 249.12 W/m² |
| D. | 149.12 W/m² |
| Answer» C. 249.12 W/m² | |
| 302. |
If radiant energy EB emitted by the black surface strikes the non-black surface. If non-black surface has absorptivity α, it will absorb how much radiations? |
| A. | α EB |
| B. | 2 α EB |
| C. | 3 α EB |
| D. | 4 α EB |
| Answer» B. 2 α EB | |
| 303. |
What is the symbol used for time? |
| A. | M |
| B. | H |
| C. | K |
| D. | T |
| Answer» E. | |
| 304. |
If a black body at 1000 K and a gray body at 1250 K emit the same amount of radiation, what should be the emissivity of the gray body? |
| A. | 0.3096 |
| B. | 0.4096 |
| C. | 0.5096 |
| D. | 0.6096 |
| Answer» C. 0.5096 | |
| 305. |
The approximate distribution of the flow of sun’s energy to the earth’s surface is |
| A. | 53% is reflected back to space |
| B. | 53% is transmitted to the earth |
| C. | 9% is scattered |
| D. | 22% is absorbed in the atmosphere |
| Answer» D. 22% is absorbed in the atmosphere | |
| 306. |
Consider a beam of monochromatic radiation at wavelength λ that enters a layer of absorbing gas. As the beam passes through the gas layer, its intensity is given by |
| A. | d I λ X = – K λ I λ X d x |
| B. | d I λ X = – 2 K λ I λ X d x |
| C. | d I λ X = – 3 K λ I λ X d x |
| D. | d I λ X = – 4 K λ I λ X d x |
| Answer» B. d I λ X = – 2 K λ I λ X d x | |
| 307. |
When the sun lies at a mean distance from the earth, the heat flux from the sun to the outer edge of the atmosphere has been found to be |
| A. | 2350 W/m² |
| B. | 3350 W/m² |
| C. | 4350 W/m² |
| D. | 1350 W/m² |
| Answer» E. | |
| 308. |
Find the shape factor F 12 for the arrangement shown in the figure. The areas A 1 and A 2 are perpendicular but do not share the common edge |
| A. | 0.03 |
| B. | 0.04 |
| C. | 0.05 |
| D. | 0.06 |
| Answer» C. 0.05 | |
| 309. |
The net heat interchange between non-black bodies at temperature T 1 and T 2 is given by |
| A. | f₁₂ F₁₂ σ (T₁⁴ – T₂⁴) |
| B. | f₁₂ F₁₂ A₁ σ (T₁⁴ – T₂⁴) |
| C. | f₁₂ A₁ σ (T₁⁴ – T₂⁴) |
| D. | F₁₂ A₁ σ (T₁⁴ – T₂⁴) |
| Answer» C. f₁₂ A₁ σ (T₁⁴ – T₂⁴) | |
| 310. |
A thin shield of emissivity E3 on both sides is placed between two infinite parallel plates of emissivities E1 and E2 and temperatures T1 and T2. If E1 = E2 = E3, then the fraction radiant energy transfer without shield takes the value |
| A. | 0.25 |
| B. | 0.50 |
| C. | 0.75 |
| D. | 1.25 |
| Answer» C. 0.75 | |
| 311. |
What is the symbol used for convective film coefficient? |
| A. | v |
| B. | h |
| C. | σ |
| D. | µ |
| Answer» C. σ | |
| 312. |
A furnace emits radiation at 2000 K. Treating it as a black body radiation, calculate the wavelength at which emission is maximum |
| A. | 1.449 * 10¯⁶ m |
| B. | 2.449 * 10¯⁶ m |
| C. | 3.449 * 10¯⁶ m |
| D. | 4.449 * 10¯⁶ m |
| Answer» B. 2.449 * 10¯⁶ m | |
| 313. |
What is the value of fouling factor for fuel oil? |
| A. | 0.0009 m² K/W |
| B. | 0.0010 m² K/W |
| C. | 0.0011 m² K/W |
| D. | 0.0012 m² K/W |
| Answer» C. 0.0011 m² K/W | |
| 314. |
Some of the gases have low emissive power and absorptivity. They are considered practically diathermanous. Which of the following option is true? |
| A. | Ammonia |
| B. | Helium |
| C. | Carbon-dioxide |
| D. | Methane |
| Answer» C. Carbon-dioxide | |
| 315. |
The law governing the distribution of radiant energy over wavelength for a black body at fixed temperature is referred to as |
| A. | Kirchhoff’s law |
| B. | Planck’s law |
| C. | Wein’s formula |
| D. | Lambert’s law |
| Answer» C. Wein’s formula | |
| 316. |
The temperature of the photosphere, referred to as the effective temperature of the sun, is usually taken as |
| A. | 3000 K |
| B. | 4000 K |
| C. | 5000 K |
| D. | 6000 K |
| Answer» E. | |
| 317. |
Reflectivity is defined as |
| A. | Fraction of total energy transmitted by the body |
| B. | Fraction of energy reflected by the body |
| C. | Fraction of total energy absorbed by the body |
| D. | Fraction of total energy absorbed and radiated by the body |
| Answer» C. Fraction of total energy absorbed by the body | |
| 318. |
The energy emitted by a black surface should not vary in accordance with |
| A. | Wavelength |
| B. | Temperature |
| C. | Surface characteristics |
| D. | Time |
| Answer» E. | |
| 319. |
Likewise the amount of emitted radiation is strongly influenced by the wavelength even if temperature of the body is |
| A. | Constant |
| B. | Increasing |
| C. | Decreasing |
| D. | It is not related with temperature |
| Answer» B. Increasing | |
| 320. |
On clear night there is radiation from earth’s surface to the space. On such a night, the water particles on the plant leaves radiate to the sky whose temperature may be taken as 200 K. The water particles receive heat by convection from the surrounding air, the convection heat transfer coefficient has a value of 30 W/m² K. If the water should not freeze, make calculations for the air temperature |
| A. | 280.474 K |
| B. | 345.645 K |
| C. | 123.456 K |
| D. | 874.387 K |
| Answer» B. 345.645 K | |
| 321. |
“A surface element emits radiation in all directions, the intensity of radiation is however same in different directions. Choose the correct answer |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 322. |
“Isothermal furnaces, with small apertures, approximate a black body and are frequently used to calibrate heat flux gauges”. Chose the correct answer |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» B. False | |
| 323. |
The sensitivity of thermocouple is defined as the time required by thermocouple to reach how much percentage of its steady state values? |
| A. | 43.3 |
| B. | 53.2 |
| C. | 63.3 |
| D. | 73.3 |
| Answer» D. 73.3 | |
| 324. |
“The response of a thermocouple is defined as the time required for the thermocouple to reach the surrounding temperature when it is exposed to it”. Choose the correct answer |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 325. |
The response time for different sizes and materials of thermocouple wires usually lie between |
| A. | 0.04 to 2.5 seconds |
| B. | 0.06 to 1.2 seconds |
| C. | 0.02 to 0.04 seconds |
| D. | 2.4 to 9.4 seconds |
| Answer» B. 0.06 to 1.2 seconds | |
| 326. |
A thermocouple junction of spherical form is to be used to measure the temperature of the gas stream. The junction is at 20 degree Celsius and is placed in a gas stream which is at 200 degree Celsius. Make calculations for time required by the thermocouple to reach 197 degree Celsius temperature. Assume the thermos-physical properties as given belowk = 20 W/ m Kh = 350 W/m² Kc = 0.4 k J/kg Kp = 8000 kg/m³ |
| A. | 1.094 seconds |
| B. | 2.094 seconds |
| C. | 3.094 seconds |
| D. | 4.094 seconds |
| Answer» E. | |
| 327. |
An egg with mean diameter of 4 cm and initially at 25 degree Celsius is placed in an open boiling water container for 4 minutes and found to be boiled at a particular level. For how long should a similar egg boil at the same level, when refrigerator temperature is 5 degree Celsius? Use lumped parameter theory and assume following properties of eggk = 12 W/m Kh = 125 W/m² Kc = 2 k J/kg Kp = 1250 kg/m³ |
| A. | 251.49 seconds |
| B. | 261.49 seconds |
| C. | 271.49 seconds |
| D. | 281.49 seconds |
| Answer» D. 281.49 seconds | |
| 328. |
Of the radiant energy 350W/m² incident upon a surface 250W/m² is absorbed, 60W/m² is reflected and the remainder is transmitted through the surface. Workout the value for absorptivity for the surface material |
| A. | 0.113 |
| B. | 0.114 |
| C. | 0.115 |
| D. | 0.116 |
| Answer» D. 0.116 | |
| 329. |
The value of transmissivity may vary from |
| A. | 0-1 |
| B. | 1-2 |
| C. | 3-4 |
| D. | 4-5 |
| Answer» B. 1-2 | |
| 330. |
A cavity with a small hole will always behave as a |
| A. | White body |
| B. | Transparent body |
| C. | Black body |
| D. | Opaque body |
| Answer» D. Opaque body | |
| 331. |
“Transmissivity can also be defined as ratio of transmitted radiation to that of incident energy flow”. True or false |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 332. |
What is the wavelength band of gamma rays? |
| A. | 1 * 10¯⁷ to 4 * 10¯⁴ micron meter |
| B. | 2 * 10¯⁷ to 2.4 * 10¯⁴ micron meter |
| C. | 3 * 10¯⁷ to 3.4 * 10¯⁴ micron meter |
| D. | 4 * 10¯⁷ to 1.4 * 10¯⁴ micron meter |
| Answer» E. | |
| 333. |
HEAT_CAN_TRAVEL_ONLY?$ |
| A. | Upwards |
| B. | Downwards |
| C. | Upwards and Downwards |
| D. | None of the mentioned |
| Answer» E. | |
| 334. |
A cold body contains no heat. The statement i? |
| A. | Correct |
| B. | Incorrect |
| C. | Always correct |
| D. | None of the mentioned |
| Answer» C. Always correct | |
| 335. |
Q = 45 means |
| A. | Heat is transferred from the system |
| B. | Heat is transferred from surrounding |
| C. | Heat is gained by the surrounding |
| D. | None of the mentioned |
| Answer» C. Heat is gained by the surrounding | |
| 336. |
If Q = 45 W and The values of U and A are 10 and 2.5 with their respective SI units. What is the temperature difference between system and surrounding? |
| A. | 1.8 Degree Celsius |
| B. | 1.8 Degree Fahrenheit |
| C. | 1.8 Degree Rankine |
| D. | None of the mentioned |
| Answer» B. 1.8 Degree Fahrenheit | |
| 337. |
When Q = 0, there is possibility that |
| A. | Temperature of system and surrounding are same |
| B. | System is an adiabatic system |
| C. | Both a and b |
| D. | Neither a nor b |
| Answer» D. Neither a nor b | |
| 338. |
When Heat is gained by the system |
| A. | Q < 0 |
| B. | Q > 0 |
| C. | Q = 0 |
| D. | None of the mentioned |
| Answer» C. Q = 0 | |
| 339. |
Heating always results in an increase in temperature. The statement is |
| A. | Correct |
| B. | Incorrect |
| C. | Always correct |
| D. | None of the mentioned |
| Answer» C. Always correct | |
| 340. |
Two state are given as following |
| A. | |
| B. | |
| Answer» C. | |
| 341. |
Heat transfer can occur by |
| A. | Conduction |
| B. | Convection |
| C. | Radiation |
| D. | All of the mentioned |
| Answer» E. | |