|September 26 | Tata Steel | Wipro | HDFC AMC | Fortis Healthcare | BASM

 Tata Steel: Global credit rating agency Moody’s has upgraded the corporate family rating of Tata Steel from Ba1 to Baa3, and changed the outlook from Positive to Stable. The rating agency expects the company's profitability to increase even as softer steel prices dent revenues, and the company to maintain conservative financial policies with a well-balanced capital allocation and financial metrics appropriate for its Baa3 rating.

Wipro: The IT services company announced the sale of land measuring 14 acres and 02 cents, in Chennai, together with a 20-year-old building for Rs 266.38 crore. The company executed the sale deed on September 25 and Casagrand Bizpark was the buyer.

Fortis Healthcare: The company has received approval from the board of directors to enter into a Share Purchase Agreement for acquiring a 99.9% stake in Artistry Properties. The enterprise value of the stake buy is Rs 32 crore. Artistry owns a land and building adjacent to Fortis Hospital at Anandpur in Kolkata. The building is entirely constructed with all statutory compliances in place and with minimal customization and re-layout, it can be utilized for accommodating OPD, diagnostics, and daycare services, relocated/shifted from the main building of Fortis Anandpur Hospital.

HDFC Asset Management Company: HDFC AMC has invested Rs 25 crore in its subsidiary HDFC AMC International (IFSC) and continues to hold a 100% stake in the subsidiary.

Bannari Amman Spinning Mills: Shareholders have given approval for the reappointment of S V Arumugam as Managing Director of Bannari Amman Spinning Mills, for three years with effect from June 27, 2023, to June 26, 2026. They also approved an appointment of C Sivasamy as an Independent Director of the Company for 5 consecutive years, from June 28, 2023 to June 27, 2028.

Electrical Engineers: Basic Interview Questions

 What are the primary responsibilities of an electrical engineer?

The primary responsibilities of an electrical engineer are to create, design, test, and observe the electrical components of a project. This is a vast field, and projects within this field can vary from manufacturing products to designing power grids. Due to its vast field, the responsibilities can vary from position to position.

The key responsibilities of an electrical engineer are as follows:

• Fixing and troubleshooting of devices.
• Conducting the functionality tests.
• Analyzing current trends and information.
• Developing manufacturing processes for building and assembling electrical components etc.

What are the critical skills required to become an electrical engineer?

The main task of an electrical engineer is to take care of the components of the electrical system. To prevent and troubleshoot such failures, a skilled electrical engineer must do the following things:

• Analyze data to get top trends.
• Communicate clearly with supervisors and clients to get the decision efficiently.
• Keep up to date on emerging trends within the industry.
• Adhere to strict safety codes.
• Work in tandem with supervisors and management.

What are the fundamental components of electrical circuits?

Following are the fundamental components of electrical circuits:

• Active Circuits: Active Circuits are the elements used to generate energy from within their system as a form of source.
• Passive Circuits: Passive circuits are the elements that allow the electric current to pass through it and do not generate any energy from it.
• AC or DC Circuits: AC stands for Alternating Current, and DC stands for Direct Current. AC always produces some fluctuating current, whereas DC always produces a stable current in a constant source.
• Series Circuits: When the electrical components are connected in series within a circuit, it is known as a series circuit.
• Parallel Circuits: When the electrical components are connected in parallel within a circuit, it is known as a parallel circuit.

What is the definition of an ideal transformer?

A transformer is called an ideal transformer if there no losses happen at all. In other words, we can say that, in an ideal transformer, the transformer input authority should be equivalent to the output authority of the transformer, i.e., they have 100% competence.

What are the different types of networks used to build an electrical circuit?

There are mainly two types of networks used to build an electrical circuit called Passive or Active Networks. A Passive network is a network that contains passive elements in its network, such as Resistance, Capacitance, or Inductance. On the other hand, an Active Network is a network that contains active elements in its network, such as Current or Voltage Sources.

What are some essential tools used for the measurement of electrical parameters in an electrical circuit?

Following is the list of some measuring tools used for the measurement of electrical parameters:

• Voltmeter
• Ammeter
• Ohmmeter
• Multi-meter
• Power meter
• Microwave meter
• Cathode Ray Oscilloscope
• Signal Generators and Analyzers
• Wattmeter
• Sweep Generator etc.

Gas Insulated Substations (GIS)

 

High Voltage Gas Insulated Substations (GIS) are one-time installations having a very long operating life with minimal maintenance, unlike Air Insulated Substations (AIS). However, being a complex and high-cost construction, the operation and maintenance of GIS is still an elusive topic that requires a closely coordinated plan and schedule based on the manuals and instructions of OEMs.

They draw a lot of similarities, as well as quite a few differences from their conventional counterpart, AIS.

After its inception in the mid-1960s, GIS technology has become a remarkable success over a wide range of high voltage applications up to 800 kV. Reliable operation and compact size have been its main advantages over its conventional air-insulated counterparts. Despite a very high initial capital cost, these two advantages reflect in other multiple aspects like low maintenance, minimum footprint, enhanced safety, pleasing aesthetics, and so on.

Operating a GIS module could be a challenge for untrained operators because of completely encapsulated switchgear, measuring equipment, and conducting parts. Although the components and operations are principally similar to an AIS, the physical arrangement of those elements marks a notable difference.

The presence of metallic enclosure and unavailability of visible indication of component operations require getting used to. Furthermore, a GIS module requires stringent interlocking schemes between breakers, maintenance switches, and earthing switches to ensure safe operation and maintenance.

WORKING PRINCIPLE OF VFD

It is important to be familiar with the working principle of VFDs as they are extensively used in AC motor-driven applications. VFD has greater functionality and operation capabilities than conventional motor drives, which will be explained in detail in this article.

Let’s take a 3-phase load as an example to see how VFDs work. Firstly, when AC power is supplied from the mains, it directly passes through the first VFD stage – Rectifier stage. The current passes through six diodes that convert the AC-supplied current into DC. In short, each of the three phases is connected to one pair of diodes, which only allow the peak of each phase to pass through it.

Therefore, the output of the 3 phases passing through diodes, when measured by an oscilloscope.

the output current looks like a rough DC or just a current wave that doesn’t include the negative side of the current. Therefore, this current needs to be converted into a healthy DC and the best way to achieve that is by connecting a capacitor that will smooth the output current.

This capacitor is the VFD’s second stage, called the DC filter. Because of the charging and discharging effect of the capacitor, the current passing through the DC filter will have a wave.

After the DC is considered smooth, it is ready to pass through the third stage of the VFD – the IGBTs inverter to convert it into AC again. When the current reaches this stage, the converted AC’s frequency could be varied accordingly. The connected number of IGBTs here will be turned on and off very fast to produce an AC-like waveform that will run the connected motor as if it was connected directly to an AC supply.

The IGBTs here act like switches that when rapidly switched on and off, create the Pulse-Width Modulation (PWM) that is a key to allowing a VFD to control the speed of the motor.

Variable Frequency Drive (VFD)

 

For many years, the major challenge to some motor-driven applications was the inability to control their speed. However, the advent of reliable power electronics made it possible to control the speed of motors using variable-frequency drivers.

VFDs are widely used in many applications nowadays. The main reason is that they have greater functionality and operation capabilities compared to conventional motor drives when starting a motor.

The working of VFD is based on the control of frequency and voltage simultaneously through a PWM inverter, it is used to control the speed of AC motor-driven applications. In addition, variable frequency drives offer protections like phase, under, and overvoltage protection.

Components of VFD

To understand the working principle of a variable frequency driver, it is important to know what it is composed of. In other words, you need to know what leads the currents passing through a VFD of a 3-phase motor, for instance, to be changed from AC to DC and then back to AC again.

VFD comprises three main sections: Rectifier, Filters, and Inverter.

1. Rectifier: The first stage of VFD. It converts AC power fed from the mains to DC power. It mainly utilizes diodes that are connected in parallel to convert AC power into DC.
2. Filter: A capacitor that is used to smooth the rectified DC power.
3. Inverter: Transistors (IGBTs) used to work to be switched on and off rapidly to create a pulse-width modulation which creates an AC-like wave that will allow the VFD to control the speed of the motor.

"Why Do You Want To Work Here?"

 

"Why Do You Want To Work Here?"

The hiring manager is trying to get at your underlying motivations for wanting this job. Are you here just for a paycheck, or do you see yourself becoming an integral part of the company and growing along with it?

You need to show them that you want to become “part of the family.” At the same time, however, show how your “wants” coincide with their “needs.”

EXAMPLE ANSWER:

“One thing that really attracted me to your company and this opportunity is the company’s dedication to its local community. I’m a community-oriented person, both on and off the job. Along with preferring a work environment with an exceptional culture – such as the one your company offers – I value employers that look outside their walls for opportunities to make a difference. I feel your company does that to a degree you don’t typically see, and I want to be a part of a business like that.”

"What Is Your Greatest Strength?"

"What Is Your Greatest Strength?"

This is a fairly straightforward question to handle. Talk about a “strength” that you know the company puts a lot of value in.

EXAMPLE ANSWER:

“My biggest strength is my problem-solving capabilities. Generally, I’m a methodical person with exceptional research skills. However, I’m also comfortable thinking outside of the box. When taken together, that allows me to navigate the unknown with greater ease. I know how to track down the information I need, as well as how to look deeper, creating opportunities to innovate when I need solutions.”