RRB JE ECE (CBT II) Mock Test- 7 - Electronics and Communication Engineering (ECE) MCQ

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

Green plants are most likely to produce greenhouse gases.

• Greenhouse gases consists gases such as carbon dioxide, methane, water vapour, nitrous oxide and ozone.
• These gases absorbs heat which produced from the Sun.
• A greenhouse is called so because it is a house which contains green things such as plants and beneficial gasses.

Solid grounding is adopted for voltages below 600 V because of the higher point-of-fault energy levels. A power system is said to be effectively grounded or solidly grounded when the neutral of a generator, power transformer or grounding transformer are directly connected to the ground through a conductor of negligible resistance and reactance.

Let the case and junction temperature be T₁ and T₂. The thermal resistance θ_R = 1°C/W. Then power
dissipated P_D is given by,
P_D = T₂ - T₁/θ_R
⇒ T₁ = T₂ - P_D . θ_R
⇒ T₁ = 200 - 100 × 1 = 100°C
Thus, the case temperature should be, T₁ = 100°C

• Crooked Glass can cut off the UV rays.
• It is a special type of glass which contains Cerium Oxide [CeO2].
• It is used in making sunglasses.

Incineration is a waste treatment process that involves the combustion of organic substances contained in waste materials. Incineration and other high-temperature waste treatment systems are described as "thermal treatment". Incineration of waste materials converts the waste into ash, flue gas and heat means in the presence of air

Q = 7 - 15
Q = 5.5 C

Global e-commerce giant ‘Amazon’ has entered, into the ed tech space with the launch of its first ed tech app in India called ‘JEE Ready’ for IIT JEE.
Hence, the correct option is (B)

Self explanatory as per the list of precedence given by the constitution
Hence, the correct option is (C)

• Continue is also a loop control statement just like the break statement
• continue statement is opposite to that of break statement, instead of terminating the loop, it forces to execute the next iteration of the loop
• When the continue statement is executed in the loop, the code inside the loop following the continue statement will be skipped and next iteration of the loop will begin

Syntax: continue;

• When i=3 condition in if expression becomes true then Testbook won’t be printed else it will be printed
• loop will run 6 times but Testbook will be printed for 5 times

Hence, the correct option is (C)

• The electron beam in an oscilloscope can be deflected in two directions.
• One is horizontal (x-direction) and the second vertical (y-direction).
• When two inputs are applied at horizontal and vertical plates, two dimensional displays are produced as a result.

Hence, the correct option is (D)

The "Mean" is the "average" = 150 + 165 + 161 + 144 ++ 155/5 = 775/5 = 155
The "Median" is the "middle" value in the list of numbers, given number is 144,150,155,161 and 165, middle value of given 
numbers is 155 i.e. median of given number is 155
Mean = 155 and median = 155 
Hence, the correct option is (B)

The twinkling of a star is due to atmospheric refraction of starlight. The starlight, on entering the earth’s atmosphere, undergoes refraction continuously before it reaches the earth.

The atmospheric refraction occurs in a medium of gradually changing refractive index.

Since the atmosphere bends starlight towards the normal, the apparent position of the star is slightly different from its actual position.

8051 is a 8-bit microcontroller with 40 pin chip. It has 4 8-bit input ports (P₀, P₁, P₂, P₃) port P₁ is a general purpose I/O port while P₀, P₂, P₃ have additional function associated with them based on context of their usage.

• To turn OFF the conducting SCR, the anode or forward current of SCR must be reduced to zero or below the level of holding current and then an enough reverse voltage must be applied across the SCR to regain its forward blocking state
• The reverse voltage which causes to commutate the SCR is called commutation voltage.
• A conducting SCR can be opened by reducing the anode current to zero

FF + 01 = 1 00 H

The accumulator contains 00 H

And 1 carry is obtained

The important point to note here that though carry is obtained but carry flag will not be used because INR instruction does not affect carry flag.

• World Brain Day is observed on July 22 every year.
• The day aims at promoting interest of neurology. Previously, World Brain Day has covered topics like dementia, epilepsy and stroke, in cooperation with other societies.
• World Brain Day 2019 theme is Migraine: The Painful Truth.
• This year, the focus is on migraine, which is known to be one of world's most common brain diseases.

Band stop filter using Parallel L and C is shown

• At low frequencies, L is a short circuit and passes low frequencies
• At High frequencies, Capacitor C acts as a short circuit and passes high frequencies
• But at mid-frequency say Resonant frequency parallel L-C circuit behaves as an open circuit and the output voltage V_out is zero

Concept:
The drift velocity is related to electric field and mobility by
v  = μ_n E
Calculations:
900m / s = μ_n 15 V / cm

μ_n = 600 cm²/V-sec

• The Dead Sea is a salt lake which is bordered by Jordan to the east and Israel to the west.
• The Dead Sea lies in the Jordan Rift Valley, with the Jordan River as its main tributary.
• Its surface and shores are 430.5 meters (1412 feet) below sea level.

Burden of a protective relay is the power absorbed by the relay circuit. It is expressed in volt amperes (VA).

Mass of solute (salt) = 40 g

Mass of solvent (water) = 320 g

We know,

Mass of solution = Mass of solute + Mass of solvent

= 40 g + 320 g

= 360 g

mass percentage of solution = mass of solute / mass of solution x 100

mass percentage of solution = 40/360 x 100 = 11.11 %

Gateway is used to connect system from one layer of TCP/IP to another layer of TCP/IP.

A gateway device provides communication to a remote network or an autonomous system that is out of bounds for the host network nodes.

Gateways serve as the entry and exit point of a network; all data routed inward or outward must first pass through and communicate with the gateway in order to use routing paths

Other Networking Devices and their functions are:

The truth table for modulus-2 addition is

S = A'B + AB'

C = AB

Mac OS is developed by Apple. Mac OS is a series of graphical operating systems which is developed and marked by Apple. Windows 7 is developed by Microsoft. IOS is developed by Apple Inc. Bada OS was developed by Samsung Electronics.

X = ABC + ABC’ + A’B

X = AB (C + C’) + A’B

X = AB + A’B

X= B(A + A’)

X= B

Since output is equal to input B hence no NAND gate is required to implement the expression.

A barcode reader is an electronic device that can read barcodes and converts them into electric pulses to be processed by a computer. A barcode reader scans the barcode, and the CPU handle the barcode, turn them into information that we can read and it sends the data to the scanner's output port.

A transresistance amplifier has current as input and voltage as output.

For effective coupling of current to transistor, the input impedance should be small.

The output is voltage:

Hence for effective coupling of output to load, the output resistance is large.

Generally the Transresistance amplifier has low input impedance and low output impedance.

Hence in ideal case it should have Ri_n = 0 and R_out = 0

Similarly the Transconductance amplifier has high input impedance and high output impedance.

Hence in ideal case it should have R_in = ∞ and R_out = ∞

• A Schottky diode is formed between metal and semiconductor (n-type), thus there is no p-n junction in Schottky diode
• Schottky diodes have less recovery time compare to normal diodes and hence provide fast switching speeds
• Schottky diodes are used at high-frequency applications