RRB JE Electrical (CBT II) Mock Test- 3 - Electrical Engineering (EE) MCQ

The number of replaceable hydrogen atoms of an acid is called its basicity. An acid must contain at least one hydrogen atom. And some acids contain more than 20 hydrogen atoms, example:- C₁₀H₂₁COOH . All the options are correct.

In overhead transmission lines up to 100km length the capacitance can be neglected

In core type and cylinder type transformer have batter cooling since more surface exposed to the atmosphere but in shell type transformer cooling is not very effective because less surface area exposed in the atmosphere.

A circuit that uses only two states is known as a binary circuit. Circuit design with binary quantities, “on” and “off” representing 1 and 0 (i.e., true and false), uses the logic of Boolean algebra.

Gunpowder, also known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur (S), charcoal (C), and potassium nitrate (saltpeter, KNO₃). The sulfur and charcoal act as fuels while the saltpeter is an oxidizer.

• The Gross Domestic Product is defined as the total value of the finished goods and services produced within the boundary of a country in a financial year.
• The GDP of India has shown a growth of 8.2% in the first quarter of the FY 2018-19.

Given that, copper losses (W_cu) = A
Iron losses (W_i) = B
In a transformer, maximum efficiency occurs at copper losses equal to iron losses
Maximum efficiency occurs at load given by,
Load at maximum efficiency

• The International Police Organization, commonly known as INTERPOL, is an intergovernmental organization facilitating international police cooperation.
• It was established as the International Criminal Police Commission (ICPC) in 1923.
• Its headquarters are located in Lyon, France.

• Electronic mail (email) is a method of exchanging messages between people using electronic devices
• Email operates across computer networks, which today is primarily the Internet
• Many email providers have a web-based email client e.g. AOL Mail, Gmail, Outlook.com, Hotmail and Yahoo
• This allows users to log into the email account by using any compatible web browser to send and receive their email
• Mac OS is an operating system developed by Apple. It is not a web-based component

Schering bridge is used for measurement of loss angle in a dielectric.

Tan δ = ω CR

Where δ is loss angle

Important:

• Kelvin double bridge is used to measure low value of resistance in the range of 0.001Ω.
• Maxwell’s bridge, Hay’s bridge, Owen’s bridge and Anderson Bridge are most suitable for the measurement of unknown inductance.
• Carey Foster bridge is a bridge circuit used to measure medium resistances, or to measure small differences between two large resistances.

Combustion or Burning:

• Combustion is a chemical process in which a substance reacts rapidly with oxygen and gives off heat
• Waste like plastic and rubber tires can be burned using this combustion process
• These make use of the heat energy generated by the combustion & incineration process to electricity
• It is the most effective method of waste disposal at reducing the volume of solid waste
• It is not an acceptable practice, as it creates lots of pollution and it is harmful to both the environment as well as organisms

Important Points:

Recycling:

• It is the process of converting waste materials into reusable objects to prevent waste
• The materials from which the items are made can be reprocessed into new products
• Recycling such material saves the product and it also reduces the amount of manufacture to make new products
• It also helps in energy saving and reducing global climate change

Landfill or Burying:

• Landfill refers the disposal of waste material by burying it
• It is extended storage area for non-biodegradable waste
• Landfill is an area, which prevent contamination from the waste entering the area surrounding by soil and water and it also helps to reduce odour and pests

Composting:

• Due to lack of adequate space for landfills, biodegradable yard waste is allowed to decompose in a medium designed for the purpose
• Only biodegradable waste materials are used in composting
• Good quality environmentally friendly manure is formed from the compost and can be used for agricultural purposes

• The Oligopoly Market characterized by a small number of large sellers.
• Oligopolies can result from various forms of collusion which reduce competition and lead to higher prices for consumers.
• Oligopoly has its own market structure. Sellers selling homogeneous or differentiated products.

• Acetic Acid is the common name of ethanoic acid.
• The chemical Formulae for Acetic Acid is CH₃COOH.
• It belongs to a group called carboxylic acid and hence they are weak acids.
• When acetic acid is diluted in water with a percentage of 5-8 then vinegar is formed.
• The melting point of acetic acid is 290k and it often freezes at room temperature, hence it has another name called Glacial Acetic Acid.

• Under the 69^th amendment of the Indian Constitution, Special status was given to Delhi as National Capital Territory of Delhi.
• Under the 86^th amendment of the Indian Constitution, Elementary education was made a fundamental right under article 21 A.
• Under the 44^th amendment of the Indian Constitution, Right to Property was deleted as a fundamental right.
• Under the 42^nd amendment of the Indian Constitution, Preamble was amended for the first time.

Applications of thermit welding:

A thermit welding application includes joining of railway rail ends so that rail becomes continuous which makes smoother roadbed.

Repair of broken machine parts of large sections. Repair welds are normally nonrepetitive and therefore, pre-manufactured molds are not used.

Used for welding of copper conductors.

The reinforcement bars in the concrete beam is joined using the thermit welding.

Important Point:

Applications of resistance welding:

• Used by many industries to manufacture products made up of thinner gauge metals
• Used for manufacturing of tubes and smaller structural sections

Applications of carbon arc welding:

• It can be employed for the welding of stainless steel with thinner gauges
• Useful for the welding of thin high-grade nickel alloys and for galvanized sheets using copper silicon manganese alloy filler metal

Resonance in electric circuits is the phenomena, in which at a certain input voltage frequency the voltage and current drawn by the circuit are in phase.
In parallel resonant circuit at resonance frequency the impedance is maximum.
For parallel LC circuit

At resonance

Y = 0
Since Y = 0 , Z = ∞

• Induction type of energy meter are universally used for measurement of energy in domestic and industrial A.C circuit
• The unit of electrical energy is kilowatt hour (KWh)
• Induction type of energy meter used is based on the “electromagnetic induction” principle
• They are known as induction type instruments
• An induction meter can handle current up to 100 A

Impedance of tank circuit is,

Resonant frequency of tank circuit, = w = 
At resonant frequency, impedance is infinity.

A starter is necessary to start a DC motor because it restricts initial high armature current that exists, as the value of starting back-EMF is zero
Important:
A resistor is used in the starter for a DC shunt motor

• When the connected dc motor is to be started, the lever is turned gradually to the right
• When the lever touches point 1, the field winding gets directly connected across the supply, and the armature winding gets connected with resistances R1 to R5 in series
• During starting, full resistance is added in series with the armature winding
• Then, as the lever is moved further, the resistance is gradually is cut out from the armature circuit
• Now, as the lever reaches to position 6, all the resistance is cut out from the armature circuit and armature gets directly connected across the supply

• When field current is reduced, the motor pull-out torque is also reduced in proportion
• Lowering the field strength lowers the internally generated voltage (E_a)
• This is usually undesirable as it will make the machine appear inductive

An ecosystem may be defined as a structural and functional unit of the biosphere comprising living organisms and their non-living environment that interact by means of food chains and chemical cycles resulting in

• energy flow,
• biotic diversity and
• material cycling to form a stable, self-supporting system.

The organisms in an ecosystem are classified into 3 main categories

• producers,
• consumers and
• decomposers.

Note:

1. The consumers utilize materials and energy stored by the producers.
2. Decomposers obtain their food molecules from the organic materials of dead producers and consumers.
3. In a true ecosystem, producers are more than consumers (herbivores and carnivores).

The star-delta starter method of starting three-phase induction motors is very common and widely used among all the methods. In this method, the motor runs at delta connected stator windings. It is also used for small motors up to 5 kW rating.

Important Points:

The direct on line (DOL) starter methodof an induction motor is simple and economical. In this method, the starter is connected directly to supply voltage. By this method, small motors up to 5 kW rating are started to avoid the supply voltage fluctuation.