All Free Chemical Engineering MCQs with Answers
Every Chemical Engineering question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
6,983 questions · page 346 of 350
- A. Iron-constantan
- B. Platinum-platinum + rhodium
- C. Copper-constantan
- D. Chromel-alumel
Explanation: A platinum-rhodium thermocouple withstands very high temperatures and oxidizing atmospheres, making it suitable near 1600°C.
Correct answer: Platinum-platinum + rhodium6902. In an exothermic chemical reactor, the manipulated variable is the flow rate of_______________?
- A. Product
- B. Reactants
- C. Coolant
- D. None of these
Explanation: For temperature control in an exothermic reactor, coolant flow is commonly manipulated to remove more or less heat and maintain the…
Correct answer: Coolant- A. -10 to 20
- B. 400 - 1000
- C. 100 - 500
- D. 0 to 100
Explanation: A hydrogen constant-volume thermometer is commonly used over approximately 0 to 100°C, where hydrogen provides a useful reference gas.
Correct answer: 0 to 100- A. 1/(T2s2 + 2ξTs + 1)
- B. 1/(T2s2 + 2Ts + 1)
- C. 1/(T2s2 + 2ξT + 1)
- D. None of these
Explanation: The standard normalized second-order transfer function is 1/(T²s² + 2ξTs + 1), where T is the time constant and ξ is the damping ratio.
Correct answer: 1/(T2s2 + 2ξTs + 1)- A. Vapor pressure thermometer
- B. Mercury in glass thermometer
- C. Constant volume gas thermometer
- D. Resistance thermometer
Explanation: A mercury-in-glass thermometer gives a local visual reading and cannot conveniently transmit that reading over 60 metres.
Correct answer: Mercury in glass thermometer- A. < 100
- B. > 0
- C. < 0
- D. > 800
Explanation: Helium gas thermometers are particularly suitable for low-temperature measurements below 0°C because helium remains useful in the…
Correct answer: < 0- A. Bulb
- B. Bourdon tube
- C. Pointer
- D. None of these
Explanation: The bulb is the primary element because it senses temperature directly through the vapor-pressure change.
Correct answer: Bulb- A. A metal powder or graphite
- B. Air
- C. Oil
- D. Mercury
Explanation: Air is a poor heat-transfer medium and creates a large thermal resistance between the bulb and thermal well, slowing response.
Correct answer: Air- A. Alumel
- B. Chromel
- C. None of these
- D. Constantan
Explanation: Alumel and Chromel are nickel-containing alloys, while Constantan is a copper-nickel alloy and also contains nickel.
Correct answer: None of these- A. Triple point of hydrogen and freezing point of antimony
- B. 13.81°K to 903.9°K
- C. Neither A. nor B.
- D. Both A. and B.
Explanation: The standard platinum resistance thermometer range extends from the triple point of hydrogen, 13.81 K, to the freezing point of antimony…
Correct answer: Both A. and B.- A. Critically damped
- B. Overdamped
- C. Underdamped
- D. Highly fluctuating
Explanation: A damping ratio of unity means the two characteristic roots coincide on the negative real axis, giving the fastest response without…
Correct answer: Critically damped- A. Flow rates of granular solids
- B. Flow rates of fluids
- C. Very high temperature
- D. Thermal conductivity of gases
Explanation: A hot-wire anemometer measures fluid velocity by detecting the cooling of a heated wire, and the velocity can be converted into flow rate.
Correct answer: Flow rates of fluids- A. Platinum-platinum + rhodium
- B. Iron-constantan
- C. Chromel-alumel
- D. None of these
Explanation: A chromel-alumel thermocouple, also called Type K, develops roughly 31 to 33 mV at 800°C when referenced to 0°C.
Correct answer: Chromel-alumel- A. Lead
- B. Nickel
- C. Copper
- D. 30% iron + 70% nickel
Explanation: Lead is not normally used as the sensing element of an industrial resistance thermometer because its resistance-temperature…
Correct answer: Lead- A. Chromel-alumel thermocouple
- B. Optical pyrometer
- C. Radiation pyrometer
- D. Either B. or C.
Explanation: Molten iron and slag are too hot for ordinary contact thermometers, so non-contact optical or radiation pyrometers are used.
Correct answer: Either B. or C.- A. Decibel = 20 loge (AR)
- B. Decibel = 20 log10 (AR)
- C. Decibel = 20 log10 (AR)0.5
- D. Decibel = 20 loge (AR)0.5
Explanation: For an amplitude ratio, the decibel value is defined as 20 times the base-10 logarithm of the ratio: dB = 20 log10(AR).
Correct answer: Decibel = 20 log10 (AR)- A. 12
- B. 36
- C. 54
- D. 68
Explanation: Invar is an iron-nickel alloy containing approximately 36% nickel, which gives it an exceptionally low coefficient of thermal expansion.
Correct answer: 36- A. Liquid level under pressure
- B. Frequency of light
- C. Depression of freezing point
- D. Rpm of a flywheel
Explanation: A stroboscope makes a rotating object appear stationary when the flashing frequency matches its rotational frequency, allowing its rpm to…
Correct answer: Rpm of a flywheel- A. Servo problem
- B. Transient response
- C. Frequency response
- D. Regulator problem
Explanation: A control response caused by a change in set point is called a servo problem or servo response.
Correct answer: Servo problem- A. Thermal conductivity cell
- B. Hot wire anemometer
- C. Polarograph
- D. Mass spectrometer
Explanation: A hot-wire anemometer measures fluid velocity or flow, not composition.
Correct answer: Hot wire anemometer