Engineering :: Energy Conversion

@ : Home > Mechanical Engineering > Energy Conversion

241.

Wooden poles for supporting transmission lines are used for voltages upto

A.	440 V	B.	11 kV
C.	22 kV	D.	66 kV

242.

The expected life of wooden poles is

A.	1 year	B.	5 years
C.	15 years	D.	50 years

243.

Skin effects depends upon

A.	size of the conductor	B.	frequency of the current
C.	resistivity of the conductor	D.	All of the above

244.

The skin effect of a conductor will reduce as

A.	the diameter increases	B.	the frequency increases
C.	the permeability of conductor material increases	D.	the resistivity of conductor material increases

245.

Skin effects is proportional to

A.	diameter of conductor	B.	(diameter of conductor)
C.	(diameter of conductor)2	D.	(diameter of conductor)3

246.

For constant voltage transmission, the drop is compensated by installing

A.	synchronous motors	B.	capacitors
C.	inductors	D.	All of the above

247.

The disadvantage of constant voltage transmission is

A.	short circuit current of the system is increased	B.	low power factor in heavy loads
C.	large conductor area is required for same power transmission	D.	All of the above

248.

Pin insulators are normally used upto voltages of about

A.	100 kV	B.	66 kV
C.	33 kV	D.	25 kV

249.

Strain type insulators are used where the conductors are

A.	dead ended	B.	at intermediate anchor towers
C.	any of the above	D.	None of the above

250.

The effect of corona is

A.	increased energy loss	B.	increased reactance
C.	increased inductance	D.	increased susceptance