Engineering Sciences
GATE XE year:2019 PYQs
Build your understanding with focused practice from past exam papers.
Questions 41–50 of 175. Imported answers require independent review unless marked reviewed.
Question 20
Open questionXE-BNAT2 marksNeeds review
In a steady incompressible flow of a fluid past a smooth stationary sphere, the drag force
depends on the flow velocity
, diameter
, and the dynamic viscosity
and density
of the fluid. Experiments are conducted on the same sphere at the same flow velocity using two different fluids. The density of the second fluid is two times that of the first fluid. The dynamic viscosity of the second fluid is
times that of the first fluid. If the non-dimensional force
remains the same in both the experiments, the value of
is ______.Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 21
Open questionXE-BNAT2 marksNeeds review
An incompressible fluid flows past a flat plate as shown in the figure below with a uniform inlet velocity profile
and a parabolic exit velocity profile
, where
is the component of velocity parallel to the wall,
is the normal distance from the plate and
. If the volume flow rate across the top surface of the control volume (CV) is
per unit width (perpendicular to the
-
plane) of the plate, the value of
(rounded off to 2 decimal places) is ______. 
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 22
Open questionXE-BNAT2 marksNeeds review
A jet engine is to be tested on a thrust stand as shown in the figure below. The conditions prevailing in a typical test are as follows: Axial intake air velocity = 100 m/s; axial exhaust gas velocity = 250 m/s; intake cross-sectional area = 1 m
; intake static pressure =
kPa (gauge); exhaust static pressure = 0 kPa (gauge); mass flow rate through the engine = 100 kg/s. The anchoring force (in kN) in axial direction on the thrust stand is ______. 
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 1
Open questionXE-CMCQ1 markNeeds review
On decreasing the objective aperture size in an optical microscope
Your answerChoose one option.
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 2
Open questionXE-CMCQ1 markNeeds review
Pilling-Bedworth ratios for oxides of some metals are given in the table.\n\n| Metal | Pilling-Bedworth Ratio |\n|---|---:|\n| Li | 0.57 |\n| Ce | 1.16 |\n| Ta | 2.33 |\n| W | 3.40 |\n\nBased on the criterion of Pilling-Bedworth ratio alone, which one of the following metals will be most protected from high temperature oxidation?
Your answerChoose one option.
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 3
Open questionXE-CMCQ1 markNeeds review
In NaCl, the substitution of a Na
ion by a Ca
ion would most probably lead toYour answerChoose one option.
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 4
Open questionXE-CMCQ1 markNeeds review
Which one of the following is time-independent?
Your answerChoose one option.
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 5
Open questionXE-CMCQ1 markNeeds review
Copper is diffused into aluminium at 400 °C for 100 hours to obtain a certain concentration at a given depth. In another experiment conducted at 500 °C, to achieve the same concentration of copper at the same depth, the time required in hours is\n\n(Given: Diffusion coefficients of copper in aluminium at 400 °C and 500 °C are
and
, respectively)Your answerChoose one option.
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 6
Open questionXE-CMCQ1 markNeeds review
If carbon (C) in iron (Fe) is 6 percent by weight, then its atomic percent is approximately\n\n(Given: atomic weight C = 12, Fe = 56)
Your answerChoose one option.
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 7
Open questionXE-CMCQ1 markNeeds review
GaAs has advantage over silicon when used in integrated circuits at low power because it has
Your answerChoose one option.
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer