AFCAT EKT Computer Science Mock Test - 2 - Computer Science Engineering (CSE) MCQ

Candidate key is A and B → C, C → B are transitive dependencies and there are no partial dependencies. Hence it is in 2 NF but not in 3 NF 

Binary number for 7 is 0111

Derived Attribute : Attributes derived from other stored attribute. For example age from Date of Birth and Today’s date.

A Boolean function can be expressed as

the product of maxterms (Which is POS form), eg. (A+B)(A'+B') or the sum of minterms (SOP) terms, eg. (AB + A'B')

Generalization is a abstracting process of viewing sets of objects as a single general class by concentrating on the general characteristics of the constituent sets while suppressing or ignoring their differences.In simple terms, Generalization is a process of extracting common characteristics from two or more classes and combining them into a generalized superclass. So, it is a bottom up approach as two or more lower lever entities are combined to form a higher level entity.

Specialization may be seen as the reverse process of Generalization. Specialization is the abstracting process of introducing new characteristics to an existing class of objects to create one or more new classes of objects.In simple terms, a group of entities in specialization can be categorized into sub - groups based on their characteristics. So it is a top - down approach in which one higher level entity can be broken down into two lower level entity. It defines one or more subtypes of the supertypes and forming supertype/subtype relationships.

Let X be a continuous random variable with range [a, b] and probability density function f(x). The expected value of X is defined by

The discrete formula says to take a weighted sum of the values x_i of X, where the weights are the probabilities p(x_i)

Also A + AT = I

According to Snell’s Law

Here μ₁ > μ₂
So 

A light ray passing through glass from denser to rarer medium. The reflected ray in the rarer medium is made obtuse angle with respect to normal.

Memory Compaction is the process of moving all the allocated blocks to one end of memory, thus combining all the holes. This is the problem of external fragmentation.

The range of n bit word in 2’s complement representation is,
(-2^n-1) to (2n^-1-1)
(n-1) is used here because out of n bits 1 bit is used as sign bit 
There is one extra negative number because "0" has only single representation in 2's complement form
For 8 bit word the range will be 127 to -128. 

When a body is immersed in a fluid, an upward force is exerted by the fluid on the body.

This upward force is equal to the weight of the fluid displaced by the body and is called the force of buoyancy.

Hamming code is an error detecting code.

The presentation layer is responsible for the delivery and formatting of information to the application layer for further processing or display. It is sometimes called the syntax layer

Since A is orthogonal, A^TA = AA^T = I

|A^TA| = |AA^T| = |I|  |A^T||A| = |A||A^T| = |I| = +1

for the car,

m_car = 1000 kg, u_car = 32 ms^-1, v_car = -8 ms^-1

for truck,

m_truck = 8000 kg, u_truck = 4 ms^-1, v_truck = ?

By conservation of linear momentum,

m_car.u_car + m_truck.u_truck = m_car v_car + m_truck.v_truck

⇒ 1000 × 32 + 8000 × 4 = 1000 × (-8) + 8000 × v_truck

⇒ v_truck = 9 ms^-1

To realize a J-K flip flop from an S-R flip flop, we should have

So, we have to use two additional AND gates.

Mainframe is a very large in size and expensive computer capable of supporting thousands of users simultaneously. Mainframe executes many programs concurrently.

Minicomputer is a midsize computer. A minicomputer is a multi-processing system capable of supporting up to 250 users simultaneously. A minicomputer is a computer of a size intermediate between a microcomputer and a mainframe.

A microcomputer is a complete computer on a smaller scale and is generally a synonym for, personal computer or PC, a computer designed for an individual.

Workstation is a computer used for engineering applications such as Computer Aided Design/Computer Aided Manufacturing (CAD/CAM), desktop publishing, software development, and other types of applications, which require a moderate amount of computing power and relatively high quality graphics capabilities.

The ACID Properties are –

• Atomicity: either all operations succeed or all of them fail
• Consistency: the database is changed from one consistent state to another consistent state
• Isolation: no transaction interfere other transactions in the middle
• Durability: operations of successful transactions must persist

The scattering of a photon by an electron is called the Compton effect.

The scattered photon will have less energy (more wavelength) as compare to incident photon (less wavelength).
The energy lost by the photon is taken by an electron as kinetic energy.
There are three essential requirements for the production of X-rays.
(i) A source of the electron
(ii) An arrangement to accelerate the electrons
(iii) A target of a suitable material of high atomic weight and a high melting point on which these high-speed electrons strike.

In X-ray tube, when high speed electrons strikes the target, they penetrate the target. They loses their kinetic energy and comes to rest inside the metal. The electron before finally being stopped makes several collisions with the atoms in the target. At each collision X-rays may get formed.
When the electron loses whole of its energy in a single collision with the atom, an X-ray photon of maximum energy hν_max  is emitted.

If the energy of electron increased then then wavelength of the characteristic x-ray λ is reduced.

Both TFTP and SNMP use UDP as transport layer protocol.

A zener diode works based on the tunneling of charge carriers across the junction. A zener diode is a normal diode in the forward biased. It is in the reverse biased condition that the heavy doping causes a zener to behave differently than a normal diode.

An HTTP cookie is a small piece of data sent from a website and stored on the user's computer by the user's web browser while the user is browsing.

Cookies are just strings, not code.

There are 1024 memory location 1024 = 2¹⁰
Hence, address bus width is 10 bits.
The data bus of 8 bits will be required to write/read data at each 8 bit memory location.

The ratio of lateral strain to the longitudinal strain is a constant for a given material, when the material is stressed within the elastic limit. This ratio is known as Poisson’s ratio (μ)

Belady's anomaly is a phenomenon in which increasing page numbers increases the page fault rate.

Let after time t₁ the ball reached to the topmost point where the velocity will be zero.
v_top = 0 = 20 - gt₁
⇒ t₁ = 2 sec
So the falling time of the ball is, t₂ = 6 – 2 = 4 sec
Now, difference in distance travelled = height of the tower

Shortcut: Net displacement, s = - h (negative sign as the direction of motion is opposite to the displacement)

Absolute entropy (S) or entropy is a measure of energy dispersion in a system.

Following are basic features of entropy:

• Entropy transfer is associated with heat transfer (direction of flow of entropy is same as that of heat flow)
• Entropy is proportional to mass flow in an open system
• Entropy does not transfer with work

Entropy linked with energy

During adiabatic process, there is no exchange of heat takes place between the system and surroundings. i.e. ΔQ = 0. Change in pressure (P), volume (V), temperature (T) takes place.

As there are 6 identical resources and Max requirement is 2, hence Max. number of process can be allowed is

But when the number of process is more than 5

In 8085 microprocessors, B, C, D, E, H and L are 8 bit registers and they are called as general purpose registers.