Full Test 3 - EKT CSE - AFCAT MCQ

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.

A p - n junction diode allows electric current in one direction and blocks electric current in another direction. It allows electric current when it is forward biased and blocks electric current when it is reverse biased. An actual diode offers a very small resistance (ideally zero but actually very low) when forward biased and is called forward resistance. 

According to Snell’s Law

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.

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.

Let after time t₁ the ball reached to the topmost point where the velocity will be zero.

So the falling time of the ball is, t₂ = 6 – 2 = 4 sec
Now, difference in distance travelled = height of the tower

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

Gravitational force is an attractive force that acts between any two masses. Gravitational forces are equal in magnitude but opposite in direction.

So the ratio of gravitational pull of earth on moon and that of moon on earth will be 1:1.

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

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.

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')

To get the dual of the given expression change OR to AND operator and AND to OR operator.
A+[B+(AC)]+D = A[B(A+C)]D

The range of n bit word in 2’s complement representation is,
(−2ⁿ⁻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. 

Binary number for 7 is 0111
Gray code for 7 will be 0100

(657)₈ = (110101111)₂ = (1AF)₁₆ = 1AFH

Let two binary numbers 0010 and 0011 equivalent excess-3 numbers are added

0101 + 0110 = (1011)₂ = (11)₁₀

To get equivalent binary number 0110 must subtracted from 1011. Hence the result is 0101.

Hamming code is an error detecting 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.

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

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.

The system of homogeneous linear equations has a non – trivial solution if

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)

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

We know that 1+ω+ω²=0 and ω³ =1 then
(1−ω⁸)(1−ω⁴)(1−ω²)(1−ω) = (1−ω²)(1−ω)(1−ω²)(1−ω)
= (1−ω²−ω+ω³)(1−ω²−ω+ω³)
= (2−(ω+ω²))(2−(ω+ω²))
= (2−(−1))(2−(−1)) = 9

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.

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).

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.

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.

CAD is the use of computer technology for design and design documentation. CAD/CAM applications are used to both design a product and program manufacturing processes, specifically, CNC machining. CAM software uses the models and assemblies created in CAD software to generate tool paths that drive the machines that turn the designs into physical parts.

There is change at 3rd, 4th and 5th bit from LSB.

Class A addresses range from 0.0.0.0 to 127.255.255.255. Class B addresses range from 128.0.0.0 to 191.255.255.255. Class C addresses range from 192.0.0.0 to 223.255.255.255.