Questions 381–390 of 668. Imported answers require independent review unless marked reviewed.

Topic practice 668 questionsPage 39 of 67

Question 20

Open question
XE-HNAT2 marksNeeds review
Suppose, because of the doubling of atmospheric CO₂ concentration, an ocean water column receives an additional net energy input of 1 Wm⁻². If the entire water column of depth 1 km heats up uniformly, the water temperature will increase by 1 K in ____ years (round off to the nearest integer).
Assume all the additional heat added is retained and not lost. Take density of seawater = 1000 kg m⁻³; specific heat capacity of seawater = 4200 J kg⁻¹ K⁻¹.

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

Question 21

Open question
XE-HNAT2 marksNeeds review
Consider a layer of atmosphere between 5 and 6 km height. The downwelling longwave radiation at 5 and 6 km is 240 and 230 Wm⁻², respectively. The upwelling longwave radiation at these heights is 260 and 240 Wm⁻², respectively. The longwave heating rate in this layer is ____ K per day. (Round off to one decimal place.)
Take the average density of air in this layer to be 0.5 kg m⁻³; Specific heat capacity of air at constant pressure = 1000 J kg⁻¹ K⁻¹.

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

Question 22

Open question
XE-HNAT2 marksNeeds review
A spherical asteroid, revolving around the sun in a circular orbit, is in radiative balance. Suddenly, the asteroid enters the shadow of a planet and solar radiation is cut off. Assuming that the asteroid emits as a blackbody in the longwave regime, the time taken to reduce the average temperature of the asteroid by 0.5 K is ____ seconds (round off to the nearest integer). Ignore the temporal change in radiation emitted by the asteroid during this cooling period. The physical properties of the asteroid are: diameter = 2 m, density = 3000 kg m⁻³, specific heat = 200 J kg⁻¹ K⁻¹ and albedo = 0.8 in shortwave radiation. Take the solar constant = 500 W m⁻², Stefan-Boltzmann constant = 5.67 × 10⁻⁸ W m⁻² K⁻⁴.

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

Question 6

Open question
XE-ANAT1 markNeeds review
Let

be a continuous function on the real line such that for any

,

. Then

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 answer

Question 7

Open question
XE-ANAT1 markNeeds review
The number of points at which the function

has local minima 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 answer

Question 11

Open question
XE-ANAT2 marksNeeds review
Players

and

take turns to throw a fair dice with six faces. If

is the first player to throw, then the probability of

being the first one to get a six is ____ (round off to two decimal places).

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

Question 8

Open question
XE-BNAT1 markNeeds review
A liquid flow through a horizontal smooth pipe of diameter 5 cm and discharges into a collection tank of dimension 50 cm x 50 cm x 50 cm. Time taken for a 10 cm rise of liquid level in the collection tank is 40 s.
The flow velocity in the pipe is ------ m/s (rounded off to two decimal places).

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

Question 9

Open question
XE-BNAT1 markNeeds review
The potential function for a two dimensional incompressible flow field is given as:

.
Magnitude of the velocity vector at point (2,1) is ________ m/s

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

Question 15

Open question
XE-BNAT2 marksNeeds review
A hydroelectric power plant takes in 30 m

/s of water through its turbine and discharges it to the atmosphere with

m/s. The total head loss in the turbine and penstock system is 20 m. (Assume turbulent flow with kinetic energy correction factor as 1.1. Density of water is 1000 kg/m

and acceleration due to gravity, g is 10 m/s

).
The net head available to the turbine for power generation is --------------- m.
(rounded off to one decimal place).
Diagram for Engineering Sciences question 15


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

Question 16

Open question
XE-BNAT2 marksNeeds review
Water flows at an average velocity,

of 10 m/s through a horizontal smooth tube of diameter,

5 cm. The friction factor,

is 0.02. Head loss is obtained using Darcy-Weisbach relation

. The fluid pressure,

measured at various stations are reported in the table below. The length of the pipe,

between station 0 and station 6 is 6 m.
Station
0
1
2
3
4
5
6

, kPa
304
273
255
240
226
213
-
If acceleration due to gravity, g = 10 m/s

and density of water =1000 kg/m

, then the fluid pressure at station 6 is ______ kPa (rounded off to one decimal place)

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