RRB JE (Railways Junior Engineer) CBT EC Test 2 Free Online Test 2026

A multipoint (also called multidrop) connection is one in which more than two specific devices share a single link.

In a multipoint environment, the capacity of the channel is shared, either spatially or temporally. If several devices can use the link simultaneously, it is a spatially shared connection. If users must take turns, it is a timeshared connection.

A bus topology describes multipoint connections. In bus topology one long cable act as a backbone to link all the devices in a network.

System software is a type of computer program that is designed to run a computer's hardware and application programs. If we think of the computer system as a layered model, the system software is the interface between the hardware and user applications.

• A web browser is a software application for accessing information on the World Wide Web
• URL is an acronym for Uniform Resource Locator, It is a reference to the resource on the internet
• A client is a computer that connects to and uses the resources of a remote computer, or server
• The server handles the request from the web browser and sends back a response to build a connection to provide web services
• Cookies are messages that web servers pass to the web browser when user visit Internet sites

• The transmission of a signal from the first earth station to satellite through a channel is called uplink

• The transmission of a signal from the satellite to second earth station through a channel is called downlink

• Uplink frequency is the frequency at which, the first earth station is communicating with the satellite

• The satellite transponder converts this signal into another frequency and sends it down to the second earth station

• This frequency is called Downlink frequency; In a similar way, the second earth station can also communicate with the first one

Yakshagana is a popular folk-theatre form of Karnataka with a long history of nearly four hundred years. It is a unique harmony of musical tradition, eye-catching costumes, and authentic styles of dance, improvised gestures and acting with its extemporaneous dialogue appealing to a wide range of the community. It is a vibrant and vigorous living form of theatre art.

Address Bus:

• On address bus lines the CPU sends out the address of the memory location that is to be written to or read from
• The number of address lines determines the number of the memory location that the CPU can address
• Address bus is unidirectional

Data Bus:

• The data bus is bidirectional
• This means CPU can read data in from memory or from a port on these lines or it can send data out to memory or to a port from these lines

System bus

• The system bus is the communication path between bus and peripherals

The input voltage must overcome the junction voltage between the gate and cathode (0.7V) and cause 7 mA to flow through the 220 Ω resistor. According to Kirchhoff’s voltage law, V_in us given by:
V_in = V_GK + I_GR
= 0.7V + (7 mA) (220 Ω) = 2.24 V

A Colpitts oscillator uses two capacitors in place of the two inductors of a Hartley oscillator.
Colpitts oscillator

Hartley oscillator

Images are also represented by bit patterns. In its simplest form, an image is composed of a matrix of pixels (picture elements), where each pixel is a small dot. The size of the pixel depends on the resolution. For example, an image can be divided into 1000 pixels or 10,000 pixels.

• 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. 

Astable Multivibrator shifts between two states thereby generating a square wave. In Bistable Multivibrator, a trigger pulse is needed for change from one stable state to another stable state (from 0 to 1 and 1 to 0) hence can be used to state binary data.

f = PQ (RS + R + 1)
f = PQ (1)
f = PQ

The home page is the first page that we see when a website is opened on the web browser. It is also called the start page or the main page, though home page is a more commonly used name. It is generally made attractive and contains various hyperlinks to different pages within the web site to attract visitors to its site. Some web sites require users to login to the web site to access the home page.

The screen is coated with fluorescent material called phosphor which emits light when bombarded by electrons. Phosphor coating for cathode ray tubes is provided on inside surface only.

• Krishna Sobti was a famous Hindi writer and essayist.
• She had won the Sahitya Akademi Award in 1980 for her novel Zindaginama.
• She was awarded the Jnanpith in 2017 for her contribution to Indian literature.
• Some of her celebrated works include Daar Se Bichhudi, Mitro Marjani, Zindaginama, Dil-o-Danish etc.

WAN is a Wide Area Network, WANs are typically used to connect comparatively large geographical area such as; a state, a country, a continent, the Internet WANs can span over a range of huge area of a 100,000-kilometre radius >WANs have its ownership and management is distributed, it cannot be handled at the individual level

A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus etc.

LANs can span over a limited range i.e. of 1 km in radius MAN is Metropolitan Area Network and is used to connect two or more LANs in a common geographic area: say a city or a group of buildings MANs can span in the range of 5 to 50 kilometres in diameter.

A personal area network, or PAN, is a computer network that enables communication between computer devices near a person. The range of a PAN typically is a few meters. Examples of wireless PAN, devices include cell phone headsets, wireless keyboards, wireless mice, printers, bar code scanners and game consoles.

The natural environment components can be classified into two

1. Abiotic components
2. Biotic components

Abiotic components
These components are not living but can support other living organisms. Some kinds of such organisms are given below:

• Inorganic substances: The elements which are taken up by the plants with the help of sunlight and converted into food. The examples of such inorganic elements are like nitrogen, calcium, phosphorus, hydrogen, carbon dioxide and oxygen.
• Organic substances: The substances which are taken in the form of inorganic materials from the food source and are again sent back to the environment after decomposition by decomposers. E.g. Carbohydrates, proteins, fats etc.
• Physical factors: These factors have a direct effect on living organisms, which are climatic conditions like temperature, rainfall, wind, humidity, soil and light energy which is used by the plants for the preparation of food.
• Lithosphere: The outermost layer of the earth (i.e.) soil or land.
• Hydrosphere: Part of the earth having water resources like oceans, rivers, ponds, and lakes.
• Atmosphere: It is a cover around the earth composed by a variety of gases which protects the living organisms from various harmful cosmic radiations.

Biotic components
The area in which life is possible is called as a biosphere. All living organism in the biosphere depends upon one another and these organisms exist in the biosphere forming the following community.

• Producers: The green plants present on earth surface which produces their own food only once by the process of photosynthesis in sunlight, water, and carbon dioxide forms food for other organisms. E.g. Sugar, carbohydrates etc.
• Consumer: This organisms directly (or) indirectly depend upon the green plants for the source of food. E.g. All animals including man.
• Decomposers: These are micro-organisms which decompose the complex compounds in the dead organic matter of plants and animals and again recycle the elements into the environment. E.g. Bacteria and fungi.

​So for the given conditions:

• Biotic Components – Plants, Animals, Fungi, Insects
• Abiotic Components – Sunlight, Water, Soil.

Grouping in groups of three

Some of the features of 8257 are:

• It has four channels which can be used over four I/O devices
• Each channel has 16-bit address and a 14-bit counter
• Each channel can transfer data up to 64kb
• Each channel can be programmed independently
• Each channel can perform read transfer, write transfer and verify transfer operations
• It generates MARK signal to the peripheral device that 128 bytes have been transferred
• It requires a single-phase clock
• Its frequency ranges from 250Hz to 3MHz
• It operates in 2 modes, i.e., Master mode and Slave mode

The main function of the earth wire is to prevent live wire from overloading and absorbs the excess electrons & flows to the ground. The size of the earth wire is determined by the ampere capacity of the service wires. Minimum size of earth wire for light circuit is 1 mm square for copper and 1.5 mm square for aluminum.

• Acetic acid, commonly named ethanoic acid, is a colorless liquid organic compound with the chemical formula CH₃COOH.
• When undiluted, it is sometimes called glacial acetic acid.

• Avalanche breakdown occurs in lightly-doped p-n junctions where the depletion region is comparatively long
• The doping density controls the breakdown voltage
• The temperature coefficient of the avalanche mechanism is positive; that is, as the temperature increases, so do the reverse breakdown voltage
• The magnitude of the temperature coefficient also increases with an increased breakdown voltage
• For example, the temperature coefficient of an 8.2 V diode is in the range 3 - 6 mV/K while the temperature coefficient of an 18 V diode is in the range of 12 - 18 mV/K

Concatenation operator || Concatenate columns or character strings to other columns is SQL.
eg. SELECT ‘Name’ || enamename FROM emp;

Output will be:
Name = JONES
Name = SMITH
So, one can merge the output of 2 or more columns together using concatenation operator ||.

• If the input frequency is 50 Hz, the output frequency will be 100 Hz
• ripple frequency at the output is two times of input frequency
• timeperiod = 1/f = 1/100 = 10msec

• A large collector base reverse bias is the reason behind early effect manifested by BJTs
• The depletion layer penetrates more into the base as the base is lightly doped increasing the concentration gradient in the base
• As reverse biasing of the collector to base junction increases, depletion region penetrates more into the base, this reduces the effective base width
• This reduction in base width causes less recombination of carriers in the base region
• This is known as an early effect

n-bit Johnson ring counter has 2n states.

Thus, if a Johnson counter has n states then the number of flip flops required are N/2.

The "deflection sensitivity" is defined as the ratio of the deflection of the electron beam at the screen of the CRT to the deflection voltage. Unit of deflection sensitivity of CRO is meter/volt

A toggle key toggles the input from other keys on the keyboard between different input modes.

• The most commonly used toggle key is the caps lock key, which alternates the letter keys between uppercase and lowercase
• Num lock is another toggle key which helps to input numerals from the numeric keyboard and is turned on by default
• Scroll lock key allows arrow keys to scroll through window's contents and allows users to scroll without depending on the scroll bar
• The insert key is another example of a toggle key, and it toggles between overtype mode and insert mode while entering text

• When the object is between the centre of curvature and focus or between focus and pole of a concave mirror, the image formed is virtual, erect and magnified.
• Therefore, doctors use concave mirrors to examine the eyes, ears, nose,and throat from a close range as the image formed is enlarged and provides a better view to the doctor.