# Estimation and Costing Notes for SSC JE Electrical

By Ashwani Jain|Updated : July 20th, 2022

Estimation and Costing is an importamt subject in electrical engineering section. It can be easily completed with the help of effective estimation & costing notes for SSC JE electrical. From the SSC JE previous year's electrical papers analysis, it has been observed that about 3 to 5 questions come from estimation & costing in the SSC JE Prelims every year. Electrical Engineering aspirants who are preparing for the exam can score easily in this subject if they properly practise estimation & costing questions for SSC JE electrical.

Read on to know what type and how difficult questions are asked from the Estimation and Costing subject and set your SSC JE electrical study plan accordingly.

## Estimation and Costing for SSC JE Electrical

Aspirants preparing for SSC JE exam should have good practice and command over estimation & costing questions. Well-designed and premium estimation & costing notes PDF will help the aspirants complete the topic effectively. it will also help in understanding the concepts well by which aspirants can easily tackle the estimation & costing questions for SSC JE Exam. Aspirants must check the SSC JE Syllabus as well to prepare in an efficient manner.

Candidates must practice estimation & costing questions for SSC JE as it helps to increase your speed & accuracy. Aspirants should also refer to SSC JE mock test as it helps you analyze what type of questions were asked in the past years and also help you to identify the difficulty level of the questions.

## Estimation and Costing Questions for SSC JE Electrical

Electrical engineering aspirants preparing for the SSC JE exam can refer to the following Estimation and Costing questions for SSC JE to get an idea of the difficulty level of the question that is asked in the SSC JE Paper-1 exam. Candidates must check the previous years SSC JE Question Paper to analyze the trend and difficulty level of the question paper.

1.As per IE rules the permissible variation of voltage at the consumer end is:

A. ±6%
B. ±10%
C. ±12%
D. ±2%

Solution ||| Indian Electricity Rules
As per Rule 54. Declared voltage of supply to consumer:
Except with the written consent of the consumer or with the previous sanction of the State Government a supplier shall not permit the voltage at the point of commencement of supply as defined under rule 58 to vary from the declared
voltage-.
1. in the case of low or medium voltage, by more than 6 per cent; or
2. in the case of high voltage, by more than 6 per cent on the higher side or by more than 9 per cent on the lower side; or
3. in the case of extra high voltage, by more than 10 per cent on the higher side or by more than 12.5 per cent on the lower side:]

PROVIDED that in the case of high voltage, the voltage variation limit of 12.5 per cent may continue till the 31st March, 1974.]

2.Which of the following set of IE rules related to additional provisions for use of energy at high and extra high voltage –

A. IE Rule – 50
B. IE Rule – 61
C. IE Rule – 64A
D. IE Rule – 44A

Solution ||| IE Rule 50 is about supply and use of energy.
IE Rule 61 is about connection with earth.
IE Rule 64 A is about additional provisions for use of energy at high and extra high voltage.
IE Rule 44 A is about intimation of accident.

3.According to IE rules maximum load on a power board should not exceed ....... watts.

A. 1000
B. 1500
C. 3000
D. 800

Solution |||

According to IE rule:

(1) for power board:

(1) maximum outlet from power board is restricted to two.

(2) maximum load power should not exceed 3000 Watt from power board.

(2) for light and fan:

(1) maximum outlet is restricted to 10 points.

(2) maximum load for single equipment is restricted to 800 Watt.

4.Which IE rule gives instruction for the restoration of persons suffering from electric shock.

A. IE Rule 37
B. IE Rule 38
C. IE Rule 39
D. IE Rule 44

Solution |||

Some rule as gives:

IE Rule 30: for services lines and apparatus on consumer’s premises.

IE rule 37: for supply to vehicles, cranes etc.

IE rule 38: for cable and portable and transportable apparatus.

IE rule 39: for protection of cables by bituminous materials.

IE rule 44: Instruction for the restoration of person suffering from electric shock.

IE rule 73: for supply to X-ray and high frequency installation.

5.According to IE rules for service connection for low and medium voltage line, the height of service line conductors erected across a street must NOT be less than:

A. 5.490 m
B. 5.975 m
C. 6.10 m
D. 5.18 m

Solution |||

According to IE Rule 1956.

1. No conduction of an overhead line, including service.

⇒ Erected across a street shall at any part thereof be at a hight of less than:

1. For low and medium voltage line → 5.8 meter
2. for high voltage line → 6.1 meter

When erected along a street then

1. for low and medium voltage line → 5.5 meter
2. for high voltage line → 5.8 meter

6.The method of speed control adopted in 25 kW, single-phase, 50 Hz traction is:

A. Tap changing control of transformer
B. Reduced current method
C. Series-parallel control
D. Rheostatic control

Solution |||

Single-phase AC system:

In this system of track electrification, usually AC series motors are used for getting the necessary propelling power. The distribution network employed for such traction systems is normally 15-25 kV at reduced frequency of Hz or 25 Hz. The main reason of operating at reduced frequencies is AC series motors that are more efficient and show better performance at low frequency. These high voltages are stepped down to suitable low voltage Of V by means of step-down transformer. Low frequency can be obtained from normal supply frequency with the help of frequency converter.

Low-frequency operation of overhead transmission line reduces the line reactance and hence the voltage drops directly, and single-phase AC system is mainly preferred for main line services where the cost Of overhead structure is not much importance more-over rapid acceleration and retardation is not required for suburban services.

7.An ideal traction system should have:

A. High starting tractive effort and self-contained and compact locomotive of train unit.
B. Equipment and capable of withstanding large temporary overloads of high efficiency and low initial as well as maintenance cost.
C. Easy speed control
D. All of the above

Solution |||

Requirements of ideal traction system: Normally, no single traction system fulfills the requirements Of ideal traction system, why because each traction system has its merits and suffers from its own demerits, in the fields of applications. The requirements of ideal traction systems are:

1. Ideal traction system should have the capability of developing high tractive effort in order to have rapid acceleration.
2. The speed control of the traction motors should be easy.
3. Vehicles should be able to run on any route, without interruption.
4. Equipment required for traction system should be minimum with high efficiency.
5. It must be free from smoke, ash, dun, etc.
6. Regenerative braking should be possible, and braking should be in such a way to cause minimum wear on the break shoe.
7. Locomotive should be self-contained, and it must be capable of withstanding over-loads.
8. Interference to the communication lines should be eliminated while the locomotive running along the track.

8.The wiring system that is suitable for temporary installations is

A. Conduit wiring
B. Casing and caping wiring
C. Cleat wiring
D. B and C both

Solution |||

Cleat wiring:

it the cheapest system of internal wiring. It is suitable, for temporary installations in dry places. Not suitable for use is domestic premises.

Casing and Caping wiring:

suitable for low voltage domestic installations is dry places, where there is no risk of fire hazard.

Conduit wiring:

used in workshops, go downs, public buildings and it can also be used in places where there is a possibility of fire hazards.

9.In the layout of sub-circuit wiring connection, of which cross sectional area of copper conductor is preferred?

A. 0.8 mm2
B. 1.0 mm2
C. 1.2 mm2
D. 1.5 mm2

Solution |||

In the layout of wiring connection only the Cu & Al is used a conducting wire. In the sub circuit wiring connection the cross-sectional area of Cu & Al are 1.0 mm2 & 1.5 mm2 respectively. While in the power wiring connection the cross-sectional area of Cu & Al are 1.5 mm2 & 2.5 mm2 respectively.

10.Which type of earthing is suitable in transmission lines

A. Rod earthing
B. pipe earthing
C. strip earthing
D. plate earthing

Solution |||

• Strip and Wire earthing:This etching is done in a place where the ground is rocky which means there is more rock in the ground. This earthing is widely used in long-distance transmission lines
• Rod Earthing: This type of earthing is done by digging very deep in the sandy area as the moisture content is high across the sandy place. That’s why we use Pipe Earthing in this
• Pipe Earthing: This is the most commonly used earthing in which we put a pipe 5 to 10 feet into the ground
• Plate Earthingis considered to be the best earth. This is used in substation and power station Plate Earthing Nose. Such earthing is used in places where a large number of current flows
• Coil earthingis used in the smallest amount. This earthing uses a coil made of G.I wire. Such earthing is mostly used for electric poles.

11.Official systematic, scientific study of energy consumption by the related organisation for cost reduction and energy conservation is

A. energy policy
B. energy audit
C. (a) and (b) both
D. None of the above

Solution |||

Official systematic, scientific study of energy consumption by the related organisation for cost reduction and energy conservation is energy policy and audit.

12.Materials used in plate earthing are

A. Wood coal
B. Salt, earthing plate
C. (a) and (b) both
D. None of the above

Solution |||

In plate earthing, the earthing plate is placed deep into a pit (usually dug up to 2-3 meters), along with wood coal (absorbs and retains moisture) and salt (creates an ionic solution for faster dissipation of current). The plate is connected via a Copper conductor, or GI Conductor or concealed copper cable to the respective electrical set-up.

13.Which motor is used in electric traction system?

A. DC Series Motor
B. DC Shunt Motor
C. Universal Motor
D. Reluctance Motor

Solution |||

In electric traction system DC series motor is used. A series-wound DC motor has a low resistance field and armature circuit. Because of this, when voltage is applied to it, the current is high, the advantage of high current is that the magnetic fields inside the motor are strong, producing high torque (turning force), so it is ideal for starting a heavy object like a train.

14.State whether the following statements regarding electric traction are true or false.

(a) Provision of a negative booster is essential in the case of electric traction.

(b) Communication lines that run parallel to the power supply lines of electric traction stiffer from electrical interference.

A. (a) False, (b) False
B. (a) True, (b) True
C. (a) False, (b) True
D. (a) True, (b) False

Solution |||

Provision of a negative booster is essential in the case of electric traction. By avoiding the flow of return currents through earth, it curtails corrosion of underground pipe work and interference with telegraph and telephone circuits.

15.In case of staircase wiring which type of switch is used?

A. 2 one-way switches
B. 1 one-way switch
C. 2 two-way switch
D. 1 two-way switch

Solution |||

Staircase wiring is commonly used for the staircase and corridor lighting. Normally, only a single light lamp is provided in a staircase which is controlled by either of the two switches – one installed at the top and other at the bottom. Similar is the situation in a bathroom common to two rooms & the light lamp in the bathroom can be controlled by the switches installed in the two rooms.

## Estimation and Costing Syllabus for SSC JE

The following are the topics that are needed to be covered in Estimation and Costing for SSC JE Electrical.

• Estimation of Lighting Scheme
• Electric Installation of Machines And Relevant IE Rules
• Earthing Practices And IE Rules