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MCQOPTIONS
This section includes 5314 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 2101. |
The __________ method limits the number of documents in the result set. |
| A. | limit() |
| B. | limitOf() |
| C. | limitBy() |
| D. | none of the mentioned |
| Answer» B. limitOf() | |
| 2102. |
Which of the following method corresponds to Order by clause in SQL? |
| A. | sort() |
| B. | order() |
| C. | orderby() |
| D. | all of the mentioned |
| Answer» B. order() | |
| 2103. |
Which of the following method is called while accessing documents using the array index notation? |
| A. | cur.toArray() |
| B. | cursor.toArray() |
| C. | doc.toArray() |
| D. | all of the mentioned |
| Answer» C. doc.toArray() | |
| 2104. |
Which of the following method returns true if the cursor has documents? |
| A. | hasMethod() |
| B. | hasNext() |
| C. | hasDoc() |
| D. | all of the mentioned |
| Answer» C. hasDoc() | |
| 2105. |
When you query a collection, MongoDB returns a ________ object that contains the results of the query. |
| A. | row |
| B. | cursor |
| C. | colums |
| D. | none of the mentioned |
| Answer» C. colums | |
| 2106. |
A single mode fiber has refractive indices n1=1.50, n2 = 2.23, core diameter of 8μm, wavelength = 1.5μm cutoff wavelength = 1.214μm. Find the radius of curvature? |
| A. | 12 mm |
| B. | 20 mm |
| C. | 34 mm |
| D. | 36 mm |
| Answer» D. 36 mm | |
| 2107. |
A multimode fiber has refractive indices n1 = 1.15, n2 = 1.11 and an operating wavelength of 0.7μm. Find the radius of curvature? |
| A. | 8.60μm |
| B. | 9.30μm |
| C. | 9.1μm |
| D. | 10.2μm |
| Answer» C. 9.1μm | |
| 2108. |
In the given equation, state what αr suggests? |
| A. | Radius of curvature |
| B. | Refractive index difference |
| C. | Radiation attenuation coefficients |
| D. | Constant of proportionality |
| Answer» D. Constant of proportionality | |
| 2109. |
The effects of intrinsic absorption can be minimized by ___________ |
| A. | Ionization |
| B. | Radiation |
| C. | Suitable choice of core and cladding components |
| D. | Melting |
| Answer» D. Melting | |
| 2110. |
Absorption losses due to atomic defects mainly include ___________ |
| A. | Radiation |
| B. | Missing molecules, oxygen defects in glass |
| C. | Impurities in fiber material |
| D. | Interaction with other components of core |
| Answer» C. Impurities in fiber material | |
| 2111. |
In the formula σc=\(\frac{(R_1)_v}{W_t}\) , what is (R1)v ? |
| A. | Point load |
| B. | Eccentric load |
| C. | UVL |
| D. | UDL |
| Answer» C. UVL | |
| 2112. |
Calculate the direct compressive stress when the reaction force is 15340N and the thickness and width of the crank web are 46mm and 75mm? |
| A. | 8.43N/mm2 |
| B. | 4.44N/mm2 |
| C. | 5.54N/mm2 |
| D. | 3.68N/mm2 |
| Answer» C. 5.54N/mm2 | |
| 2113. |
Calculate the width of the crank web when the diameter of crankpin is 65mm? |
| A. | 57.3mm |
| B. | 74.1mm |
| C. | 63.7mm |
| D. | 80.6mm |
| Answer» C. 63.7mm | |
| 2114. |
The maximum compressive stress should be less than which stress? |
| A. | Allowable tensile stress |
| B. | Allowable compressive stress |
| C. | Allowable shear stress |
| D. | Allowable bending moment |
| Answer» C. Allowable shear stress | |
| 2115. |
The right-hand crank web is subjected to which stress due to radial component. |
| A. | Tensile |
| B. | Compressive |
| C. | Normal strain |
| D. | Linear stress |
| Answer» C. Normal strain | |
| 2116. |
In the formula Mt=Pt×r, what is Mt? |
| A. | Couple |
| B. | Bending moment |
| C. | Torsional moment |
| D. | Shear moment |
| Answer» D. Shear moment | |
| 2117. |
Which are the two forces experienced by the crank pin? |
| A. | Bending and shear moment |
| B. | Two couple force |
| C. | Force and torsional moment |
| D. | Bending and torsional moment |
| Answer» E. | |
| 2118. |
In the formula Pr=PqSin(θ+Φ), what is Pr? |
| A. | The radial component at crankpin |
| B. | Pressure component at crankpin |
| C. | The tangential component at crankpin |
| D. | Vector component at crankpin |
| Answer» B. Pressure component at crankpin | |
| 2119. |
In the formula Pt=PqSin(θ+Φ), what is Pt? |
| A. | The pressure at crankpin |
| B. | The lateral component at crankpin |
| C. | The tangential component at crankpin |
| D. | Power at crankpin |
| Answer» D. Power at crankpin | |
| 2120. |
In the formula SinΦ=\(\frac{sin\theta}{L/r}\), what is L? |
| A. | Lateral shift |
| B. | Length of connecting rod |
| C. | Linear bending |
| D. | Length of stroke |
| Answer» C. Linear bending | |
| 2121. |
The relationship between Φ and θ is given by? |
| A. | SinΦ=\(\frac{sin\theta}{L/r}\) |
| B. | CosΦ=\(\frac{sin\theta}{L/r}\) |
| C. | SinΦ=\(\frac{sin\theta}{L\times r}\) |
| D. | CosΦ=\(\frac{cos\theta}{L/r}\) |
| Answer» B. CosΦ=\(\frac{sin\theta}{L/r}\) | |
| 2122. |
What is the crank angle from the TDC position for diesel engines? |
| A. | 35° to 45° |
| B. | 25° to 35° |
| C. | 30° to 40° |
| D. | 20° to 30° |
| Answer» D. 20° to 30° | |
| 2123. |
What is the crank angle from the TDC position for the petrol engine? |
| A. | 30° to 40° |
| B. | 35° to 45° |
| C. | 25° to 35° |
| D. | 20° to 30° |
| Answer» D. 20° to 30° | |
| 2124. |
The maximum torque is due to which component of force on the crank pin? |
| A. | Perpendicular |
| B. | Parallel |
| C. | Concentric |
| D. | Tangential |
| Answer» E. | |
| 2125. |
For semiconductors, the resistivity is inversely proportional to the temperature for semiconducting materials. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 2126. |
EF = (Ec+ Ev)/2, this represents the Fermi energy level of which of the following? |
| A. | Extrinsic semiconductor |
| B. | N-type semiconductor |
| C. | P-type semiconductor |
| D. | Intrinsic semiconductor |
| Answer» E. | |
| 2127. |
What is the Fermi energy of a n-type semiconductor?a) Eb) E(F) = (Ec + Ev)/2c) EF = (Ec + Ed)/2d) EF = (Ev + E |
| A. | E |
| B. | E(F) = (Ec + Ev)/2 |
| C. | EF = (Ec + Ed)/2 |
| D. | /2d) EF = (Ev + Ea)/2 |
| Answer» D. /2d) EF = (Ev + Ea)/2 | |
| 2128. |
The conductivity of germanium at 20°C is 2/ohm m. What is its conductivity at 40°C? Eg=0.72eV |
| A. | 1.38×10-23/Ohm m |
| B. | 1.0002/Ohm m |
| C. | 293/Ohm m |
| D. | 313/Ohm m |
| Answer» C. 293/Ohm m | |
| 2129. |
A silicon plate of thickness 1mm, breadth 10mm and length 100mm is placed in a magnetic field of 0.5 Wb/m2 acting perpendicular to its thickness. If 10-3 A current flows along its length, calculate the Hall voltage developed, if the Hall coefficient is 3.66×104 m3/Coulomb. |
| A. | 1.83×10-3 Volts |
| B. | 3.66×10-4 Volts |
| C. | 0.5 Volts |
| D. | 25.150 Volts |
| Answer» B. 3.66×10-4 Volts | |
| 2130. |
The intrinsic carrier density at room temperature in Ge is 2.37×1019/m3. If the electron and hole mobilities are 0.38 and 0.18 m2/Vs respectively. Calculate its resistivity. |
| A. | 0.18ohm m |
| B. | 0.460ohm m |
| C. | 0.4587ohm m |
| D. | 0.709ohm m |
| Answer» E. | |
| 2131. |
A semiconducting crystal 12mm long, 5mm wide and 1mm thick has a magnetic flux density of 0.5Wb/m2 applied from front to back perpendicular to largest faces. When a current of 20mA flows length wise through the specimen, the voltage measured across its width is found to be 37μV. What is the Hall coefficient of this semiconductor? |
| A. | 37×10-6 m3/C |
| B. | 3.7×10-6 m3/C |
| C. | 3.7×106 m3/C |
| D. | 0 |
| Answer» C. 3.7×106 m3/C | |
| 2132. |
Which method can be used to distinguish between the two types of carriers? |
| A. | Hall effect |
| B. | Rayleigh method |
| C. | Doppler effect |
| D. | Fermi effect |
| Answer» B. Rayleigh method | |
| 2133. |
What will happen if the maximum theoretical nozzle exhaust velocity tends to a very large value? |
| A. | Working fluid ceases to be a gas |
| B. | The temperature of the working fluid increases exponentially |
| C. | The thermal energy content of the fluid becomes infinite |
| D. | The flow undergoes rapid compression |
| Answer» B. The temperature of the working fluid increases exponentially | |
| 2134. |
What is the pressure ratio for the maximum theoretical value of nozzle outlet velocity? |
| A. | Infinite |
| B. | Zero |
| C. | Finite value < 1 |
| D. | Finite value > 1 |
| Answer» B. Zero | |
| 2135. |
What is the expression for the maximum theoretical value of the nozzle outlet velocity (ve) with an infinite expansion, if γ represents the ratio of specific heats, To represents the chamber temperature, R is the gas constant? |
| A. | ve = \(\sqrt{(2\gamma RT_o(\gamma-1))}\) |
| B. | ve = \(\sqrt{(2\gamma RT_o/(\gamma-1))}\) |
| C. | ve = \(\sqrt{(2(\gamma+1)RT_o/(\gamma-1))}\) |
| D. | ve = \(\sqrt{(2(\gamma-1)RT_o(\gamma+1))}\) |
| E. | with an infinite expansion, if γ represents the ratio of specific heats, To represents the chamber temperature, R is the gas constant?a) ve = \(\sqrt{(2\gamma RT_o(\gamma-1))}\) b) ve = \(\sqrt{(2\gamma RT_o/(\gamma-1))}\) c) ve = \(\sqrt{(2(\gamma+1)RT_o/(\gamma-1))}\) d) ve = \(\sqrt{(2(\gamma-1)RT_o(\gamma+1))}\) |
| Answer» C. ve = \(\sqrt{(2(\gamma+1)RT_o/(\gamma-1))}\) | |
| 2136. |
What are the standardized chamber pressure and exit pressure values used for comparing the specific impulse values or various design parameters of different rocket engines? |
| A. | 1000 psia, 1 atm |
| B. | 1000 atm, 1 psia |
| C. | 100 psia, 1 atm |
| D. | 100 atm, 1 psia |
| Answer» B. 1000 atm, 1 psia | |
| 2137. |
Which of the following will improve the performance of a rocket engine? |
| A. | Decrease in gas temperature |
| B. | Increase in the molecular mass of the propellant |
| C. | Decrease in the pressure ratio |
| D. | Increase in the chamber pressure |
| Answer» E. | |
| 2138. |
What is the correct definition of the nozzle area expansion ratio? |
| A. | The ratio of nozzle exit area to the throat area |
| B. | The ratio of the nozzle area at the inflection point to the throat area |
| C. | The ratio of throat area to the nozzle inlet area |
| D. | The ratio of throat area to the area at the point of inflection |
| Answer» B. The ratio of the nozzle area at the inflection point to the throat area | |
| 2139. |
The area of a de Laval Nozzle is directly proportional to the ratio v/V, where v is the flow velocity and V is the specific volume. |
| A. | True |
| B. | False |
| Answer» C. | |
| 2140. |
If the rocket exhaust gases are calorically perfect and have a mean molecular mass of 28 kg/kmol, and a constant specific heat ratio (γ) of 1.33, determine the nozzle exit velocity. Assume the nozzle inlet conditions to be the following: P1 = 5 MPa, V1 = 240 m/s, T1 = 750 K and exit pressure (Pe) to be 1 MPa. |
| A. | 204 m/s |
| B. | 699.21 m/s |
| C. | 712.32 m/s |
| D. | 805.56 m/s |
| E. | to be 1 MPa.a) 204 m/sb) 699.21 m/sc) 712.32 m/sd) 805.56 m/s |
| Answer» E. to be 1 MPa.a) 204 m/sb) 699.21 m/sc) 712.32 m/sd) 805.56 m/s | |
| 2141. |
If at a point along the isentropic rocket nozzle, the temperature of the gas is 718 K, and the flow velocity is 150 m/s, determine the nozzle exit velocity, given the exhaust gas temperature is 460 K (Assume Cp = 1005 J/kg K) |
| A. | 840.25 m/s |
| B. | 735.58 m/s |
| C. | 913.07 m/s |
| D. | 374.95 m/s |
| Answer» C. 913.07 m/s | |
| 2142. |
Which of the following will happen if there is a flow obstruction in the nozzle inner wall? |
| A. | Local conversion of kinetic to thermal energy |
| B. | Local drop in pressure around the region of obstruction |
| C. | Formation of normal shock waves at the point of obstruction |
| D. | Rapid decrease in mass flow rate |
| Answer» B. Local drop in pressure around the region of obstruction | |
| 2143. |
How can you change “Hansen” into “Nilsen” in the “LastName” column in the Persons table? |
| A. | UPDATE Persons SET LastName=’Hansen’ INTO LastName=’Nilsen’ |
| B. | MODIFY Persons SET LastName=’Nilsen’ WHERE LastName=’Hansen’ |
| C. | MODIFY Persons SET LastName=’Hansen’ INTO LastName=’Nilsen’ |
| D. | UPDATE Persons SET LastName=’Nilsen’ WHERE LastName=’Hansen’ |
| Answer» E. | |
| 2144. |
Which SQL keyword is used to sort the result-set? |
| A. | ORDER BY |
| B. | SORT |
| C. | ORDER |
| D. | SORT BY |
| Answer» B. SORT | |
| 2145. |
Which SQL statement is used to return only different values? |
| A. | SELECT DIFFERENT |
| B. | SELECT UNIQUE |
| C. | SELECT DISTINCT |
| D. | SELECT ALL |
| Answer» D. SELECT ALL | |
| 2146. |
The UNION SQL clause can be used with _____________ |
| A. | SELECT clause only |
| B. | DELETE and UPDATE clauses |
| C. | UPDATE clause only |
| D. | All of the mentioned |
| Answer» B. DELETE and UPDATE clauses | |
| 2147. |
The UPDATE SQL clause can _____________ |
| A. | update only one row at a time |
| B. | update more than one row at a time |
| C. | delete more than one row at a time |
| D. | delete only one row at a time |
| Answer» C. delete more than one row at a time | |
| 2148. |
What does the ALTER TABLE clause do? |
| A. | The SQL ALTER TABLE clause modifies a table definition by altering, adding, or deleting table columns and/or constraints |
| B. | The SQL ALTER TABLE clause is used to insert data into database table |
| C. | THE SQL ALTER TABLE deletes data from database table |
| D. | The SQL ALTER TABLE clause is used to delete a database table |
| Answer» B. The SQL ALTER TABLE clause is used to insert data into database table | |
| 2149. |
With SQL, how can you return the number of not null records in the “Persons” table? |
| A. | SELECT COUNT() FROM Persons |
| B. | SELECT COLUMNS() FROM Persons |
| C. | SELECT COLUMNS(*) FROM Persons |
| D. | SELECT COUNT(*) FROM Persons |
| Answer» B. SELECT COLUMNS() FROM Persons | |
| 2150. |
With SQL, how can you return all the records from a table named “Persons” sorted descending by “FirstName”? |
| A. | SELECT * FROM Persons SORT BY ‘FirstName’ DESC |
| B. | SELECT * FROM Persons ORDER FirstName DESC |
| C. | SELECT * FROM Persons SORT ‘FirstName’ DESC |
| D. | SELECT * FROM Persons ORDER BY FirstName DESC |
| Answer» E. | |