An overhead transmission line has a span of 260 m. The weight of the conductor is 0.68 kg/m. The maximum

An overhead transmission line has a span of 260 m. The weight of the conductor is 0.68 kg/m. The maximum allowable tension in the line is 1550 kg. Maximum sag of the line should be (a) 5.8 m (b) 4.6 m (c) 2.7 m (d) 3.7 m 
by

1 Answer

Answer :

Maximum sag = (l^2)/8c
So c = T/W
c = 1550/0.68
c= 2279.4
Now Maximum sag = (260^2)/8(2279.4)
= 3.7 (d)
by

Related questions

A single-line-to-ground fault on a overhead transmission line creates

Description : A single-line-to-ground fault on a overhead transmission line creates (A) voltage sag (B) voltage swell (C) over voltage (D) voltage flicker 

Last Answer : Creates  overvoltage.

Effect of increase in temperature in an overhead transmission line is

Description : Effect of increase in temperature in an overhead transmission line is (a) to increase stress and length both (b) to decrease stress and length both (c) to decrease stress and increase length (d) None of the above 

Last Answer : D

Earth wire on EHV overhead transmission line is provided to protect the line against:

Description : Earth wire on EHV overhead transmission line is provided to protect the line against:

Last Answer : Earth wire on EHV overhead transmission line is provided to protect the line against: lightening surge

An overhead transmission line has a span of 240m between level ...

Description : An overhead transmission line has a span of 240m between level supports. What is the maximum sag if the conductor weight 727 kg/km and has a breaking strength of 6880 kg? Allow the factor of safety of 2. Neglecting wind and ice loading.

Last Answer : An overhead transmission line has a span of 240m between level supports. 1.52 m is the maximum sag if the conductor weight 727 kg/km and has a breaking strength of 6880 kg? Allow the factor of safety of 2. Neglecting wind and ice loading.

An R.C.C. beam of 25 cm width and 50 cm effective depth has a clear span of 6 metres and carries a U.D.L. of 3000 kg/m inclusive of its self weight. If the lever arm constant for the section is 0.865, the maximum intensity of shear stress, is (A) 8.3 kg/cm2 (B) 7.6 kg/cm2 (C) 21.5 kg/cm2 (D) 11.4 kg/cm2

Description : An R.C.C. beam of 25 cm width and 50 cm effective depth has a clear span of 6 metres and carries a U.D.L. of 3000 kg/m inclusive of its self weight. If the lever arm constant for the section is 0.865, the maximum intensity ... , is (A) 8.3 kg/cm2 (B) 7.6 kg/cm2 (C) 21.5 kg/cm2 (D) 11.4 kg/cm2

Last Answer : Answer: Option A

why we use aluminium conductor and not copper in transmission lines ?

Description : why we use aluminium conductor and not copper in transmission lines ?

Last Answer : Because copper conductor are costlier than aluminium conductor

A transmission line has 1 P.0 impedance on a base of 11 KV, 100 MVA. On a base of 55 KV. it will have a P.0 impedance of

Description : A transmission line has 1 P.0 impedance on a base of 11 KV, 100 MVA. On a base of 55 KV. it will have a P.0 impedance of

Last Answer : A transmission line has 1 P.0 impedance on a base of 11 KV, 100 MVA. On a base of 55 KV. it will have a P.0 impedance of 0.02 P.U

If the maximum shear stress at the end of a simply supported R.C.C. beam of 6 m effective span is 10 kg/cm2 , the share stirrups are provided for a distance from either end where, is (A) 50 cm (B) 100 cm(C) 150 cm (D) 200 cm

Description : If the maximum shear stress at the end of a simply supported R.C.C. beam of 6 m effective span is 10 kg/cm2 , the share stirrups are provided for a distance from either end where, is (A) 50 cm (B) 100 cm (C) 150 cm (D) 200 cm

Last Answer : Answer: Option C

If the maximum shear stress at the end of a simply supported R.C.C. beam of 16 m effective span is 10 kg/cm2 , the length of the beam having nominal reinforcement, is (A) 8 cm (B) 6 m (C) 8 m (D) 10 m

Description : If the maximum shear stress at the end of a simply supported R.C.C. beam of 16 m effective span is 10 kg/cm2 , the length of the beam having nominal reinforcement, is (A) 8 cm (B) 6 m (C) 8 m (D) 10 m

Last Answer : Answer: Option C

A long transmission line has considerable ……………….. effect.

Description : A long transmission line has considerable ……………….. effect. A) series capacitance B) shunt capacitance C) series inductance D) shunt inductance

Last Answer : Shunt Capacitance. 

For a transmission line open circuit and short circuit impedances are 20 Ω and 5 Ω. Then characteristic

Description : For a transmission line open circuit and short circuit impedances are 20 Ω and 5 Ω. Then characteristic impedance is: (1) 100 Ω (2) 50 Ω (3) 25 Ω (4) 10 Ω

Last Answer : For a transmission line open circuit and short circuit impedances are 20 Ω and 5 Ω. Then characteristic impedance is: 10 Ω

In an AC transmission line difference in phase of voltage at two ends of the line is due to

Description : In an AC transmission line difference in phase of voltage at two ends of the line is due to (a) System voltage (b) Insulators (c) Resistance of line (d) Reactance of line

Last Answer : reactance of line

The main consideration for operating transmission line at high voltage is

Description : The main consideration for operating transmission line at high voltage is (a) to increase efficiency only. (b) to reduce power loss only. (c) to increase power transmission capability only. (d) All of the above

Last Answer : to reduce power loss: this is because when power is generated, it is generated at a very low voltage but because it is going to be transported over a long distance it is needed to be increase in order to avoid losses on the way such as copper loss and Eddy loss.

The input impedance of a short circuited loss less transmission line of characteristic impedance 50 Ohm is

Description : The input impedance of a short circuited loss less transmission line of characteristic impedance 50 Ohm is

Last Answer : Capacitive

What type of insulator will be used if the direction of the transmission line is to be changed?

Description : What type of insulator will be used if the direction of the transmission line is to be changed?

Last Answer : Suspension type of insulator will be used if the direction of the transmission line is to be changed.

Why are shunt reactors connected at the receiving end of long transmission line system:

Description : Why are shunt reactors connected at the receiving end of long transmission line system: (1) To increase the terminal voltage (2) To compensate voltage rise caused by capacitive charging at light load (3) To improve power factor (4) None of these

Last Answer : Why are shunt reactors connected at the receiving end of long transmission line system: To compensate voltage rise caused by capacitive charging at light load

To increase power transfer capability of a long transmission line, we should:

Description : To increase power transfer capability of a long transmission line, we should:  (1) Increase line resistance (2) Increase transmission voltage (3) Decrease line reactance (4) Both (2) & (3)

Last Answer : To increase power transfer capability of a long transmission line, we should:  (1) Increase line resistance (2) Increase transmission voltage (3) Decrease line reactance (4) Both (2) & (3)

The inductance of single phase two wire power transmission line per km gets doubled when the

Description : The inductance of single phase two wire power transmission line per km gets doubled when the  (a) Distance between wires is doubled  (b) Distance between the wires is increased four fold  (c) ... the wires is increased as square of the original distance  (d) Radius of the wire is doubled

Last Answer : The inductance of single phase two wire power transmission line per km gets doubled when the Distance between the wires is increased as square of the original distance 

Galloping in transmission line conductors arises generally due to

Description : Galloping in transmission line conductors arises generally due to - (A) asymmetrical layer of ice formation (B) vortex phenomenon in light winds (C) heavy weight of line conductors (D) adoption of horizontal conductor

Last Answer : D

The inductance of a power transmission line increases with

Description : The inductance of a power transmission line increases with (A) decrease in line length. (B) increase in conductor diameter. (C) increase in spacing between phase conductors. (D) increase in load current carried by conductors.

Last Answer : The inductance of a power transmission line increases with  increase in spacing between phase conductors.

Stability of a transmission line can be increased by

Description : Stability of a transmission line can be increased by

Last Answer : Stability of a transmission line can be increased by Shunt capacitor, Series capacitor

In a transmission line if booster transformers are to be used, preferred location will be

Description : In a transmission line if booster transformers are to be used, preferred location will be  (A) At the receiving end (B) At the sending end (C) At the intermediate point (D) Anywhere in the line 

Last Answer : In a transmission line if booster transformers are to be used, preferred location will be At the intermediate point

How many insulator disc used for 33 kV transmission voltage line?

Description : How many insulator disc used for 33 kV transmission voltage line?

Last Answer : 5,As 33kv is Vrms

how the booster is connected in transmission line ?

Description : how the booster is connected in transmission line ?

Last Answer : Booster is connected in series with transmission line

An R.C.C beam of 25 cm width has a clear span of 5 metres and carries a U.D.L. of 2000 kg/m inclusive of its self weight. If the lever arm of the section is 45 cm., the beam is (A) Safe in shear (B) Is safe with stirrups (C) Is safe with stirrups and inclined members (D) Needs revision of the section

Description : An R.C.C beam of 25 cm width has a clear span of 5 metres and carries a U.D.L. of 2000 kg/m inclusive of its self weight. If the lever arm of the section is 45 cm., the beam is ( ... shear (B) Is safe with stirrups (C) Is safe with stirrups and inclined members (D) Needs revision of the section

Last Answer : Answer: Option A

Corona loss is less when the shape of conductor is:

Description : Corona loss is less when the shape of conductor is:

Last Answer : Circular

A 3 layer, total diameter of an ACSR conductor is 5 cm. Find the diameter of each strand?

Description : A 3 layer, total diameter of an ACSR conductor is 5 cm. Find the diameter of each strand?

Last Answer : A 3 layer, total diameter of an ACSR conductor is 5 cm. Find the diameter of each strand? 1 cm

Work done by a body of mass 100 kg moving along a circular path of radius 2 m with a uniform velocity of 10 m/sec is a.5000 J b.2500 J c.509.68 J d.None of the above e.Tapered bearing

Description : Work done by a body of mass 100 kg moving along a circular path of radius 2 m with a uniform velocity of 10 m/sec is a.5000 J b.2500 J c.509.68 J d.None of the above e.Tapered bearing

Last Answer : d. None of the above

A 30-m vertical column of fluid (density 1878 kg/m3 ) is located where g= 9.65 mps2 . Find the pressure at the base of the column. (Formula: pg= gρhg/k )  a. 543680 N/m2  b. 543.68 kPa (gauge)  c. Both a & b  d. None of the above

Description : A 30-m vertical column of fluid (density 1878 kg/m3 ) is located where g= 9.65 mps2 . Find the pressure at the base of the column. (Formula: pg= gρhg/k )  a. 543680 N/m2  b. 543.68 kPa (gauge)  c. Both a & b  d. None of the above

Last Answer : Both a & b

Surge impedance of overhead transmission line is normally in the order of

Description : Surge impedance of overhead transmission line is normally in the order of (a) 1- 5 ohms (c) 300 - 500 ohms (b) 20 - 30 ohms (d) 300000 - 500000 ohms

Last Answer : Surge impedance of overhead transmission line is normally in the order of 300 - 500 ohms

A long overhead transmission line is terminated by its characteristic...

Description : A long overhead transmission line is terminated by its characteristic impedance. Under this operating condition, the ratio of the voltage to the current at different points along the line will?

Last Answer : A long overhead transmission line is terminated by its characteristic impedance. Under this operating condition, the ratio of the voltage to the current at different points along the line will progressively increase from the receiving end to the sending end.

The time taken for a surge to travel a 600 km long overhead transmission line is?

Description : The time taken for a surge to travel a 600 km long overhead transmission line is?

Last Answer : The time taken for a surge to travel a 600 km long overhead transmission line is 0.002s.

If a rectangular beam measuring 10 × 18 × 400 cm carries a uniformly distributed load such that the bending stress developed is 100 kg/cm2 . The intensity of the load per metre length, is (A) 240 kg (B) 250 kg (C) 260 kg (D) 270 kg

Description : If a rectangular beam measuring 10 × 18 × 400 cm carries a uniformly distributed load such that the bending stress developed is 100 kg/cm2 . The intensity of the load per metre length, is (A) 240 kg (B) 250 kg (C) 260 kg (D) 270 kg

Last Answer : (B) 250 kg

The allowable tensile stress in mild steel stirrups, reinforced cement concrete, is(A) 1400 kg/cm2(B) 190 kg/cm2(C) 260 kg/cm2(D) 230 kg/cm

Description : The allowable tensile stress in mild steel stirrups, reinforced cement concrete, is (A) 1400 kg/cm2 (B) 190 kg/cm2 (C) 260 kg/cm2 (D) 230 kg/cm

Last Answer : Answer: Option A

The total propagation delay time from transmission to reception of signals from a ground transmitter to ground receiver with angle of elevation at 10 degrees respectively is A. 273 ms B. 239 ms C. 275 ms D. 260 ms

Description : The total propagation delay time from transmission to reception of signals from a ground transmitter to ground receiver with angle of elevation at 10 degrees respectively is A. 273 ms B. 239 ms C. 275 ms D. 260 ms

Last Answer : A. 273 ms

In case of a ‘High Voltage DC’ transmission, how many minimum conductors are required?

Description : In case of a ‘High Voltage DC’ transmission, how many minimum conductors are required?

Last Answer : In case of a ‘High Voltage DC’ transmission, how many minimum conductors are required? one

Consider the following statements: Over head transmission lines are provided with earth wires:

Description : Consider the following statements: Over head transmission lines are provided with earth wires: 1 . To protect the transmission line from direct lightning strike 2. To protect the transmission line insulation from the indirect lightning strike ... (1) 1 and 3 (2) 1 and 4 (3) 1 only (4) 2 on|y

Last Answer : Consider the following statements: Over head transmission lines are provided with earth wires: 1 . To protect the transmission line from direct lightning strike 2. To protect the transmission line insulation from the indirect lightning ... (1) 1 and 3 (2) 1 and 4 (3) 1 only (4) 2 on|y

Transmission of power by a.c. cables is impossible beyond

Description : Transmission of power by a.c. cables is impossible beyond   (a) 500 km (b) 300 km (c) 250 km (d) 45 km 

Last Answer : D

In which of the following transmission lines, the value of the Shunt admittance should be

Description : In which of the following transmission lines, the value of the Shunt admittance should be approximated to zero ? (A) A 66 kV 35 km long line (B) A 132 kV 200 km long line (C) A 220 kV 300 km long line (D) A 400 kV 500 km long line

Last Answer : In which of the following transmission lines, the value of the Shunt admittance should be approximated to zero ? (A) A 66 kV 35 km long line (B) A 132 kV 200 km long line (C) A 220 kV 300 km long line (D) A 400 kV 500 km long line

In case the height of transmission tower is increased, which of the following parameter is likely to change?

Description : In case the height of transmission tower is increased, which of the following parameter is likely to change?  (A) Resistance (B) Inductance (C) Capacitance (D) None of the above

Last Answer : In case the height of transmission tower is increased, which of the following parameter is likely to change?  (A) Resistance (B) Inductance (C) Capacitance (D) None of the above

If 3000 kW power is to be transmitted over a distance of 30 km, the desirable transmission voltage will be.

Description : If 3000 kW power is to be transmitted over a distance of 30 km, the desirable transmission voltage will be.  (A) 11 kV (B) 33 kV (C) 66 kV (D) 132 kV

Last Answer : By

The purpose of guard ring in transmission lines is to

Description : The purpose of guard ring in transmission lines is to  (1) reduce the earth capacitance of the lowest unit. (2) increase the earth capacitance of the lowest unit. (3) reduce the transmission lines losses. (4) reduce the reactance of the line

Last Answer : The purpose of guard ring in transmission lines is to reduce the earth capacitance of the lowest unit.

If a rectangular pre-stressed beam of an effective span of 5 meters and carrying a total load 3840 kg/m, is designed by the load balancing method, the central dip of the parabolic tendon should be (A) 5 cm (B) 10 cm (C) 15 cm (D) 20 cm

Description : If a rectangular pre-stressed beam of an effective span of 5 meters and carrying a total load 3840 kg/m, is designed by the load balancing method, the central dip of the parabolic tendon should be (A) 5 cm (B) 10 cm (C) 15 cm (D) 20 cm

Last Answer : Answer: Option B

An R.C.C. beam of 6 m span is 30 cm wide and has a lever arm of 55 cm. If it carries a U.D.L. of 12 t per m and allowable shear stress is 5 kg/cm2 , the beam (A) Is safe in shear (B) Is safe with stirrups (C) Is safe with stirrups and inclined bars (D) Needs revision of section

Description : An R.C.C. beam of 6 m span is 30 cm wide and has a lever arm of 55 cm. If it carries a U.D.L. of 12 t per m and allowable shear stress is 5 kg/cm2 , the beam (A) Is safe in shear (B) Is safe with stirrups (C) Is safe with stirrups and inclined bars (D) Needs revision of section

Last Answer : Answer: Option D

The section modulus of a rectangular light beam 25 metres long is 12.500 cm3 . The beam is simply supported at its ends and carries a longitudinal axial tensile load of 10 tonnes in addition to a point load of 4 tonnes at the centre. The maximum stress in the bottom most fibre at the mid span section, is (A) 13.33 kg/cm2 tensile (B) 13.33 kg/cm2 compressive (C) 26.67 kg/cm2 tensile (D) 26.67 kg/cm2 compressive

Description : The section modulus of a rectangular light beam 25 metres long is 12.500 cm3 . The beam is simply supported at its ends and carries a longitudinal axial tensile load of 10 tonnes in addition to a point load of ... 13.33 kg/cm2 compressive (C) 26.67 kg/cm2 tensile (D) 26.67 kg/cm2 compressive

Last Answer : (C) 26.67 kg/cm2 tensile

State properties of conductor material used for overhead conductor.

Description : State properties of conductor material used for overhead conductor. 

Last Answer : Following are the properties of conductor material:-   1. High conductivity :- Material should have high conductivity 2. High mechanical strength:- Material should have sufficiently high mechanical strength ... available & less costly. 9. Scrap Value: - Material should have high scrap value. 

Why ACSR conductor is used for overhead lines?

Description : Why ACSR conductor is used for overhead lines?

Last Answer : It has high tensile strength 

A block of weight 20 kg slides with an initial velocity of 2 m sec down an inclined plane on to a spring of stiffness 10 kg/cm. If the co--efficient of friction is 0.2, angle ? = 30 the ratio of maximum compession of spring, neglecting friction to that while considering friction would be a.More than one b.One c.Less than one d.Depends on the stiffness of spring e.None of the above

Description : A block of weight 20 kg slides with an initial velocity of 2 m sec down an inclined plane on to a spring of stiffness 10 kg/cm. If the co--efficient of friction is 0.2, angle ? = 30 the ratio of ... be a.More than one b.One c.Less than one d.Depends on the stiffness of spring e.None of the above

Last Answer : a. More than one

A simply supported rolled steel joist 8 m long carries a uniformly distributed load over it span so that the maximum bending stress is 75 N/mm². If the slope at the ends is 0.005 radian and the value of E = 0.2 × 106 N/mm2 , the depth of the joist, is (A) 200 mm (B) 250 mm (C) 300 mm (D) 400 mm

Description : A simply supported rolled steel joist 8 m long carries a uniformly distributed load over it span so  that the maximum bending stress is 75 N/mm². If the slope at the ends is 0.005 radian and the  value of E = 0.2 ... joist, is  (A) 200 mm  (B) 250 mm  (C) 300 mm  (D) 400 mm 

Last Answer : (D) 400 mm 

For a cantilever of effective depth of 0.5 m, the maximum span to satisfy vertical deflection limit is (A) 3.5 m (B) 4 m (C) 4.5 m (D) 5 m

Description : For a cantilever of effective depth of 0.5 m, the maximum span to satisfy vertical deflection limit is (A) 3.5 m (B) 4 m (C) 4.5 m (D) 5 m

Last Answer : Answer: Option A