MCQs of Wind Energy (Renewable Energy Engineering - 2181910)

Showing 71 to 80 out of 81 Questions

71.

Stall regulation is used with turbine

(a)	having diameter less than 25 mm
(b)	having diameter more than 25 mm
(c)	having rotor of large solidity
(d)	having rotor with pitch control

72.

if the speed of a wind stream remain unchanged while passing through the rotor,

(a)	a large power will be generated
(b)	Zero power will be generated
(c)	the flow is known as stalled flow
(d)	the speed of the rotor is very high

73.

As per Betz criteria, the maximum energy extract able by an ideal wind turbine is

74.

The maximum axial thrust occurs when interference factor α is

75.

The wind turbine rotor having law value of solidity

76.

A wind turbine designed to come into operation at a minimum wind speed is called

77.

Why is wind turbine designed to stop operation at cut out velocity?

(a)	To protect wheel against damage
(b)	To make a quick stop in emergencies
(c)	To improve the efficiency
(d)	In order to adjust the blades to wind direction

78.

What is the inherent weakness of all wind machines?

(a)	Their efficiencies
(b)	Requires powerful winds to make fan rotate
(c)	Their dependency on the wind speed
(d)	Cannot be easily repaired

79.

Why severe fluctuations in power are always undesirable in windmill?

(a)	Because they pose power oscillations problems
(b)	Damage of parts due to fluctuations
(c)	The efficiency of the plant will be reduced
(d)	Results in damage to the whole plant

80.

The wind is blowing at velocity $V$ through area $A$ at a right angle to it. The density of wind is $ρ$ . The kinetic energy of the wind is

Showing 71 to 80 out of 81 Questions