All Free Chemical Engineering MCQs with Answers

• A. Cermets
• B. Stellite
• C. Tungsten carbide
• D. High speed steel

Explanation: Broaching involves many cutting teeth and substantial wear, so broaches are commonly manufactured from high-speed steel, which retains…

• A. Notched bar impact
• B. Fatigue
• C. Tensile
• D. Hardness

Explanation: Temper brittleness reduces toughness, especially in a notched specimen, so it is revealed effectively by a notched-bar impact test.

• A. Titanium
• B. Copper
• C. Aluminium
• D. Stainless steel

Explanation: Titanium is highly resistant to chloride-rich brine and has excellent resistance to pitting and crevice corrosion, making it suitable for…

• A. Cathodic protection
• B. Anodic protection
• C. Usage of largest possible anodic area
• D. Any one of these

Explanation: Cathodic protection makes the metal surface a cathode, while using a large anodic area reduces the anodic current density.

• A. 1
• B. 4.0
• C. 8
• D. 14

Explanation: Electrical silicon steel commonly contains about 3 to 4.5% silicon, with approximately 4% being the standard figure.

• A. Polystyrene
• B. Teflon (PTFE)
• C. Bakelite (phenol formaldehyde)
• D. Perspex (PMMA)

Explanation: Perspex is polymethyl methacrylate (PMMA), a transparent, lightweight and impact-resistant material suitable for aircraft window panes.

• A. Made of glass fibre and thermoplastic resins
• B. Both 'B' & 'C'
• C. Made of thermosetting resin and glass fibre
• D. Anisotropic

Explanation: Typical FRP consists of glass fibres embedded in a thermosetting resin such as polyester or epoxy.

• A. Vickers hardness test
• B. Brinell hardness test
• C. Shore scleroscope test
• D. Rockwell hardness test

Explanation: The Shore scleroscope measures hardness from the rebound height of a diamond-tipped hammer, not from the size or depth of an indentation.

• A. Flatness
• B. Concavity/convexity
• C. Surface texture
• D. Linear displacement

Explanation: A grating or linear scale converts position into a repeating optical or electrical pattern, allowing precise measurement of linear…

• A. 30 to 70 kV DC
• B. 30 to 70 kV AC
• C. 230 V AC
• D. 230 V DC

Explanation: Industrial electrostatic precipitators use a high-voltage direct-current field, typically around 30 to 70 kV, to charge particles and…

• A. Flow nozzle
• B. Rotameter
• C. Venturimeter
• D. None of these

Explanation: A rotameter can be fitted with a control mechanism, such as an automatic valve, so it can both indicate flow and regulate it.

• A. Mercury in glass thermometer (without any covering or air gap)
• B. Bare metallic thermometer
• C. All A., B. and C.
• D. Bare vapor pressure thermometer

Explanation: Each bare thermal instrument listed can be represented by a first-order energy-balance model, with one dominant thermal capacitance and…

• A. Damped vibrator
• B. Non-interacting system of two tanks in series
• C. Interacting system of two tanks in series
• D. Mercury in glass thermometer kept in boiling water

Explanation: A mercury-in-glass thermometer has one dominant thermal storage element and therefore follows a first-order response.

• A. Corner
• B. Resonant
• C. Cross-over
• D. Natural

Explanation: The resonant frequency is the frequency at which a system's amplitude ratio reaches its maximum because dynamic amplification is greatest…

• A. Liquid temperatures only
• B. Very high temperatures only
• C. Both high and low temperatures
• D. Very low temperatures only

Explanation: A thermocouple generates a voltage over a broad temperature range, so suitable designs can measure both high and low temperatures.

• A. 1/2 S3
• B. 2/S3
• C. 2/S2
• D. 1/S3

Explanation: Since f(t)=t, its integral from 0 to t is t²/2. The Laplace transform of t²/2 is (1/2)(2/s³)=1/s³.

• A. 180° - phase lag
• B. Phase lag - 180°
• C. Phase lag + 180°
• D. Phase lag + 90°

Explanation: At the gain crossover frequency, phase margin is 180° plus the phase angle, or 180° minus the phase lag when lag is stated as a positive…

• A. Strips
• B. Wires
• C. Bars
• D. Beads

Explanation: A thermocouple requires two dissimilar metals joined to form a measuring junction, and these metals are normally provided as wires.

• A. Same as time constant
• B. Maximum change in the variable that does not change the reading of the instrument
• C. Same as transportation lag
• D. None of these

Explanation: Dead zone is the range of input change over which an instrument produces no detectable output change.

• A. π/3
• B. π/6
• C. π/12
• D. 5π/12

Explanation: The total phase lag is tan⁻¹(ωτ)+ωθ. With ωτ=0.2×5=1, the first-order lag is 45°, leaving 15° or π/12 rad for the delay, so…