Explore topic-wise InterviewSolutions in Current Affairs.

First-generation computers

The first computers used vacuum tubes for electronic circuitry and magnetic drums for memory. They were very expensive to operate their electricity consumption was high and they generated a lot of heat, which was often the cause of malfunctions. First-generation computers were communicated through machine language to perform operations, and they could only solve one problem at a time.

Input was based on punched cards and paper tape, and output was displayed on printouts. UNIVAC and ENIAC computers are examples of first-generation computing devices.

Advantages:

• For Calculation and computation.
• Payroll Processing
• Record keeping

Disadvantages:

• Required a huge space
• Too big in size
• Very slow in speed
• Low level of accuracy and reliability
• Low storage capacity
• High power consumption
• High heat generation
• Used machine language
• Difficult to maintain
• Fault finding was very difficult

Second Generation Computers

1. In second-generation computers symbolic or assembly languages were used.

2. High-level programming languages were also in use at this time, such as the early versions of COBOL and FORTRAN.

3. The memory storage used magnetic core technology.

4. Second-generation computers still relied on punched cards for input and printouts for output.

Advantages:

• Smaller in size
• Better speed
• Low power consumption
• No heat was generated.
• Better storage capacity
• More reliability
• Compact Design
• Faster than I Generation Computers.

Disadvantages:

• Needed Air conditioning environment
• Constant maintenance needed.
• No operating system

Third Generation Computers

1. The development of the integrated circuit was made use of in the third generation of computers.

2. Transistors were miniaturized and were placed on silicon chips, called semiconductors.

3. The processing speed and efficiency of computers increased.

4. Keyboards and monitors were used as input and output devices.

5. The computer system had an operating system and helped to run multiple applications simultaneously. Computers gained a lot of popularity because of small size and low cost.

Advantages: 

•  Better than first and second-generation computers
• Used high-level language
• Size got reduced further
• Speed got increased
• Much better performance 
• Much more reliability

Disadvantages:

• Initial problem with Manufactures.

Fourth Generation Computers

1. The microprocessor was used in fourth the generation computers, as thousands of integrated circuits were built onto a single silicon chip.

2. The Intel 4004 chip, developed in 1971, located all the components of the computer from the central processing unit and memory to input/output controls on a single chip.

3. In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh.

4. Network technology was introduced at this time. Fourth generation computers also saw the development of GUIs, the mouse and handheld devices.

Advantages:

• Speed and Reliability are more
• Computer occupies every walks of life.
• More superior to earlier computers.
• Computer-aided Design introduced (CAD)
• LAN (Local Area Network) and WAN (Wide area network) got introduced

Herman Hollerith machine was used in a faster way to process the US census in a faster way in the year 1890.

In 1889, Herman Hollerith invented a machine which worked on electricity for the first time. One machine was used for recording data and the other one was used for doing calculations on that recorded data. His machine was capable of reading both numbers and letters. Herman Hollerith introduced the concept of punched cards. Hollerith invented the tabulating machine that could read Information from punched cards.

Python’s dictionaries are kind of hash table type.

A tuple is another sequence data type that is similar to the list. A tuple consists of a number of values separated by commas. Unlike lists, however, tuples are enclosed within parentheses.

Lists are Python’s general purpose container, often used for collections of similar objects. Lists are mutable objects that can contain any Python data. Example : 

>my list = [ ] # make an Empty list 

>my list = [1,1.0+3j, “aperitivo”, true] # make a list containing four entities. 

A Tuple is an immutable value (can’t be changed) that can contain any Python data. They are generally used for small collectioin of data.

 Example : 

>mytuple = [1, 2, 3, 4) # create a four element tuple. 

>mytuple[2] = 4 # Error – tuple can’t be modified. > print mytuple[2], len(mytuple)

Lists are the most versatile of Python’s compound data types. A list contains items separated by commas and enclosed within square brackets ([ ]). To some extent, lists are similar to arrays in C. One difference between them is that all the items belonging to a list can be of different data type.

‘List’ is like an array, individual element of list data can be accessed using indexing and can be manipulated. “Tuples” are similar to list, but there data can be changed once created through the execution of program. ‘Set’ stores unordered values and have no index. And unlike Tuples and lists, sets can have no duplicate data. “Dictionary” is similar to what their name is. It consist of pairs of keys and thier corresponding values.

A tuple is immutable i.e. cannot be changed. It can be operated on only. 

But a list is mutable. Changes can be done internally to it. 

tuple initialization: a = (2,4,5) list initialization: a = [2,4,5]

Edison found his mother as his best teacher because she always gave a satisfactory answer to his questions and helped him in all his experiments.

Correct option is (a) a street

No, I can do nothing that affects other people’s liberty.

No, he is truly a symbol of liberty.

Edison asked his teacher different types of questions. So his teacher thought that Edison was stupid and naughty.

A reasonable consideration for the rights of others is the basis of social contract.

By allowing our liberty to be curtailed a bit.

(d) a symbol of liberty.

(a) our personal liberty

False.

Fleming’s right hand rule is used in generators to find the direction of induced current. To find the direction of current we use right hand thumb rule.

It is the electric current which originates in a conductor by use of fluctuating magnetic field around the conductor.

North pole to south pole.

The magnitude of the induced current can be increased by:
(i) Taking the conductor in the form of a coil of many turns of insulated wire.
(ii) Increasing the strength of the magnetic field used.
(iii) Increasing the rate of change of magnetic flux associated with the coil.

Fuse is used for protecting appliances due to short-circuiting or overloading. The fuse is rated for a certain maximum current and blows off when a current more than the rated value flows through it. If a fuse is replaced by one with larger ratings, the appliances may get damaged while the protecting fuse does not burn off. This practice of using fuse of improper rating should always be avoided.

• Fuse has have thin wire of short length made of tin and lead in the ratio of 75: 25%. 
• When current exceeds specified limit fuse melts and breaks the circuits thereby protecting home appliances.
• If a fuse is replaced by one with larger ratings, the appliances may get damaged while the protecting fuse does not burn off. 
• This practice of using fuse of improper rating should always be avoided.

A magnet distorts the picture as it distorts the path of electrons flowing from the electron gun towards the screen inside the tv. As electrons are negatively charged particles, their motion is distorted by a magnet. So it is these electrons, not photons, which are distorted by the magnet.

Electrical wires follow standard color coding that helps classify each wire function in the circuit. In India wires are RGB mode i.e. Red- Green- Black. Each of these RGB wire have different functions. 

1. RED = Red wire signifies the phase in electric circuit. It is the live wire which cannot be connected to another red wire or black wire. 

2. BLACK = Black wires signifies neutral wire in electric circuit. The neutral wire is connected to neutral bus bar inside an electric panel. 

3. GREEN = Green wire stands for grounding/ Earthing in electric circuit. A green wire should be on can be connected to green wire only (no other wire)

Correct answer is 5 pillows

No,

Stress = \(\frac{Magnitude\, of\, restoring\, force\, by\, solid}{area\, of\, cross−section}\)

Therefore, stress is tensor quantity

Young’s modulus is defined as the ratio of longitudinal stress to longitudinal strain. 

Y = (F/A)/(∆t/t)

Elastic Fatigue is the time (delay) required for a material to regain its original position on removing the deforming force.

Young’s Modulus,

Y = \(\frac{Stress}{Longitudinal\, Strain}\)

Y ∝ stress (for same longitudinal strain)

∴ \(\frac{Y_{steel}}{Y_{rubber}}\) = \(\frac{stress_{steel}}{stress_{rubber}}\)         (A)

(Given : Y_steel > Y_rubber),

∴ \(\frac{Y_{steel}}{Y_{rubber}}\) > 1

From eqⁿ \(\frac{stress_{steel}}{stress_{rubber}}\) > 1 or stress_steel > stress_rubber

Correct Answer is: (b) V₁ ≠ V₂ ,(c) V₁ + V₂ = V₃ 

The voltmeter reading is the potential difference across its terminals when it is connected in the circuit. The ammeter reading is the current passing through it. 

Correct option: (B) 7 : 32

Both O₂ and N₂ are diatomic.

∴ ratio of their number of molecules will be equal to ratio of their number of moles.

number of moles of O₂ = \(\cfrac{Weight\,of\,O_2}{32}\)

number of moles of N₂ = \(\cfrac{Weight\,of\,N_2}{28}\)

number of moles of O₂ = number of moles of N₂

\(\cfrac{Weight\,of\,O_2}{32}\) = \(\cfrac{Weight\,of\,N_2}{28}\)

\(\cfrac{1}{32} : \cfrac{4}{28}\)

\(\cfrac{1}{32} : \cfrac{1}{7}\)

∴ ratio is 7 : 32

Correct option: (A) Mg, 0.16 g 

2Mg + O₂ → MgO

(2x24) (32)

48 g of Mg requires 32 g of O₂

∴ 0.56 g of O₂ requires = \(\cfrac{0.56\, \times\, 48}{32}\)

= 0.84 g of Mg

∴ Mg left = 1 - 0.84 = 0.16 g

Correct option is (b) 2 g of H₂

Correct option is (a) 2.16 g

Correct option: (B) 84 

MgCO_3(s) → MgO_(s) + CO_2(g)

Molar mass of MgCO₃ = 84 g mol^-1

∴ Number of moles of MgCO₃ = \(\cfrac{20}{84}\)

= 0.238 mol

∵ 1 mole MgCO₃ gives 1 mole MgO

∴ 0.238 mole MgCO₃ will give 0.238 mole MgO.

Molar mass of MgO = 40 g mol^-1

∴ 0.238 mole MgO = 40 x 0.238

= 9.52 g MgO

∴ Theoretical yield of MgO = 9.52 g

Practical yield of MgO is 8.0 g

∴ Percentage purity = \(\cfrac{8}{9.52}\) x 100

= 84%

Correct option is (d) 0.74 g

Correct option is (a) 27 x 10¹⁰

I. 3.5 atm to mm Hg: 

1 atm = 760 mm Hg 

∴ 3.5 atm = 3.5 × 760 

= 2660 mm Hg

ii. 1520 torr to aim: 

1 atm = 760 torr

∴ 1 torr = \(\frac{1}{760}\) atrn

∴ 1520 torr = \(\frac{1520}{760}\) = atm

iii. 5 m³ to dm³ : 

1 m³ = 10 dm³

∴ 5m³ = 5 × dm³ = 5000 dm³

iv. 580 °C to Kelvin: 

T(K) = t °C + 273.15 

∴ T(K)= (580 °C) + 273.15 = 853.15 K

Correct option is (b) NO₂

The correct answer is

(c) 2 v

EXPLANATION: 

Between one extreme position to another i.e. in half the time period the K.E. increases from zero to maximum (at the mean position) and again to zero thus completing one cycle. Therefore the time period of oscillation of the K.E. = T/2 where T is the time period of the SHM. Since the frequency of SHM ν =1/T, the frequency of oscillation of the K.E. ν'=1/(T/2)=2*(1/T)=2ν. Hence the option (c).     

Social problems:

(i) Many people are rendered homeless. 

(ii) Displacement of large number of tribals without due compensation. 

(iii) Migration into the cities for settlements. 

Environmental problems : 

(i) Deforestation / loss of biodiversity 

(ii) soil erosion / ecological imbalance.

The major constituents of food are: 

1. Carbohydrates 

2. lipids 

3. proteins 

4. vitamins 

5. minerals 

6. water and 

7. fiber

Test cross is a back cross but back cross is not a test cross. 

• In a test cross, hybrid cross with homozygous recessive individuals. 
• In a back cross, hybrid cross with homozygous recessive & homozygous dominant individuals.

Haplo-Diploid-unfertillised eggs become males, fertilized eggs become females.

Both are used to determine the frequency of gene or allele. It is used in horticulture, animal breeding and in production of gene knockout organisms.

• In birds, sex determination is of ZW type, both males and females have same number of chromosomes.
• The males have autosomes plus a pair of Z- chromosomes.
• The females along with autosomes ZW chromosomes.
• The males are homogametic and produce sperms carrying one Z – chromosome along with autosomes.
• The females are heterogametic and produces 50% of ova carrying one Z – chromosome and the remaining 50% carrying one W – chromosomes.
• Sex of the individual is determined by the type of ovum fertilized.
• When an ovum containing Z chromosome is fertilized; the zygote (ZZ) develops into male.
• When an ovum containing W chromosome is fertilized; the zygote (ZW) develops into female.