← MES Jr. Grade
Past Questions
Phase lag network :
A)
Maintains constant velocity gain
B)
Increases bandwidth
C)
Decreases system stability
D)
Decreases velocity gain
A phase lag compensator is primarily used to improve the steady-state accuracy of a system without significantly changing its transient response.
1. **Steady-State Error and Gain**: A phase lag network provides a high DC gain, which reduces the steady-state error. However, it does so by attenuating the high-frequency gain.
2. **Velocity Gain (Kv)**: In the context of control systems, the velocity error constant (Kv) is related to the gain at low frequencies. While a lag compensator is designed to increase the static error constant (like Kv) relative to the open-loop gain, the actual effect of the lag network's transfer function (which has a pole closer to the origin than its zero) is to attenuate the gain at higher frequencies.
3. **Bandwidth**: A phase lag network decreases the bandwidth of the system, which helps in noise rejection but slows down the response. This contradicts option (b).
4. **Stability**: By reducing the bandwidth and shifting the crossover frequency to a lower value where the phase margin is typically higher, it generally improves or maintains stability rather than decreasing it. This contradicts option (c).
5. **Velocity Gain Analysis**: The transfer function of a lag compensator is $G_c(s) = rac{s + 1/T}{s + 1/eta T}$ where $eta > 1$. The attenuation factor is $1/eta$. This attenuation reduces the gain across the frequency spectrum above the very low-frequency range, effectively decreasing the 'velocity' of the system's response (slowing it down) and reducing the gain at the crossover frequency. In many technical contexts for competitive exams, the 'decrease in velocity gain' refers to this attenuation of the gain at higher frequencies to ensure stability and noise suppression.
Two thin parallel wires are carrying current in the same direction. The force experienced between them is :
A)
Repulsive
B)
No force exists
C)
Attractive
D)
Perpendicular to their axis joining wires
The force between two parallel current-carrying conductors can be explained using Ampere's Law and the Lorentz Force Law.
1. **Magnetic Field Generation**: According to Ampere's Law, a current-carrying wire produces a magnetic field around it. For a wire carrying current I₁, the magnetic field (B₁) at the location of the second wire is circular and perpendicular to the wire.
2. **Force Calculation**: The force (F) experienced by the second wire carrying current I₂ in the presence of the magnetic field B₁ is given by the formula F = I₂ (L × B₁), where L is the length of the wire.
3. **Direction (Right-Hand Rule)**:
- If the currents are in the **same direction**, the magnetic field produced by the first wire interacts with the current of the second wire such that the resulting force is directed toward the first wire.
- Conversely, if the currents are in opposite directions, the force is directed away from the other wire.
Therefore, parallel currents flowing in the same direction attract each other, while currents flowing in opposite directions repel each other.
- Option (a) is incorrect because repulsion occurs with opposite currents.
- Option (b) is incorrect because a magnetic field is present, thus a force must exist.
- Option (d) is incorrect because the force acts along the line joining the two wires, not perpendicular to it.
The incoming solar radiation at a place on the surface of the earth is 1.2 KW/m2 . The amplitude of the electric field corresponding to this incident power is nearly equal to :
A)
80 mV / m
B)
2.5 V / m
C)
30 V /m
D)
950 V / m
To find the amplitude of the electric field from the incident solar radiation (power density), we use the formula for the intensity (Poynting vector magnitude) of an electromagnetic wave in free space:
1. **Formula**: The average power density (Intensity, I) is given by:
I = (1/2) * ε₀ * c * E₀²
Where:
- I = 1.2 kW/m² = 1200 W/m²
- ε₀ (Permittivity of free space) ≈ 8.854 × 10⁻¹² F/m
- c (Speed of light) ≈ 3 × 10⁸ m/s
- E₀ = Amplitude of the electric field (V/m)
2. **Alternative Formula**: Using the intrinsic impedance of free space (η₀ ≈ 377 Ω or 120π Ω):
I = E₀² / (2 * η₀)
3. **Calculation**:
E₀² = 2 * η₀ * I
E₀² = 2 * 377 * 1200
E₀² = 904,800
E₀ = √904,800
E₀ ≈ 951.2 V/m
4. **Conclusion**: The calculated value of approximately 951 V/m aligns most closely with option (d) 950 V/m.
- Option (a) 80 mV/m is far too low.
- Option (b) 2.5 V/m is far too low.
- Option (c) 30 V/m is far too low.
Voltage series feedback (also called series shunt feed-back) results in :
A)
Increase in both input and output impedance
B)
Decrease in both input and output impedance
C)
Increase in input impedance and decrease in output impedance
D)
Decrease in input impedance and increase in output impedance
In feedback amplifiers, the effect on input and output impedance depends on how the feedback signal is connected (series or shunt) at the input and output ports.
1. **Input Impedance (Series Connection):** When the feedback is connected in 'series' with the input signal, the feedback voltage opposes the input voltage. This effectively increases the input impedance of the amplifier. Mathematically, Z_in(f) = Z_in(no feedback) * (1 + Aβ), where A is the open-loop gain and β is the feedback factor.
2. **Output Impedance (Shunt Connection):** When the feedback is connected in 'shunt' (parallel) at the output, the feedback network draws a portion of the output current. This results in a decrease in the output impedance. Mathematically, Z_out(f) = Z_out(no feedback) / (1 + Aβ).
Therefore, a 'Voltage Series Feedback' (also known as Series-Shunt feedback) increases the input impedance and decreases the output impedance. This configuration is ideal for creating a voltage amplifier, as it provides a high input impedance (to avoid loading the source) and a low output impedance (to ensure maximum voltage transfer to the load).
A full-adder can be made out of :
A)
Two half -adders
B)
Two half-adders and a NOT gate
C)
Two half-adders and a AND gate
D)
Two half-adders and a OR gate
A Full-Adder is a combinational circuit that adds three binary bits: two significant bits (A and B) and a carry bit (Cin) from a previous stage.
1. **Half-Adder (HA) Logic**: A half-adder takes two inputs and produces two outputs: Sum = A ⊕ B and Carry = A · B.
2. **Construction of Full-Adder using Half-Adders**:
- **First Half-Adder**: Takes inputs A and B. It produces a partial sum (S1 = A ⊕ B) and a partial carry (C1 = A · B).
- **Second Half-Adder**: Takes the partial sum (S1) and the carry-in (Cin) as inputs. It produces the final Sum (S = S1 ⊕ Cin) and another partial carry (C2 = S1 · Cin).
- **Final Carry Logic**: The final carry-out (Cout) of the full-adder is true if either the first half-adder produced a carry OR the second half-adder produced a carry. Therefore, Cout = C1 OR C2.
3. **Conclusion**: To implement a full-adder, we need two half-adders to handle the summation logic and one OR gate to combine the carry signals.
- Option (a) is incorrect because two half-adders alone cannot combine the carry signals.
- Option (b) and (c) are incorrect because NOT and AND gates do not perform the required carry-combination logic.
Choose the tense of the verb in the following sentence: 'It is raining cats and dogs outside.'
A)
Past continuous tense
B)
Past perfect continuous tense
C)
Present continuous tense
D)
Present perfect continuous tense
Step-by-step analysis of the sentence 'It is raining cats and dogs outside':
1. **Identify the Verb Phrase**: The verb phrase in the sentence is 'is raining'.
2. **Analyze the Structure**:
- 'is' is the present tense form of the auxiliary verb 'to be'.
- 'raining' is the present participle (verb + -ing).
- The structure [Subject + am/is/are + verb-ing] is the formula for the Present Continuous Tense.
3. **Determine the Meaning**: The sentence describes an action that is happening right now, at the moment of speaking, which is the primary function of the present continuous tense.
Why other options are incorrect:
- **a. Past continuous tense**: This would require the past form of the auxiliary verb ('was' or 'were'), e.g., 'It was raining'.
- **b. Past perfect continuous tense**: This would require 'had been' + verb-ing, e.g., 'It had been raining'.
- **d. Present perfect continuous tense**: This would require 'has been' + verb-ing, e.g., 'It has been raining'.
Choose the part of speech of the underlined word in the following sentence: 'The greengrocer sells vegetable.'
A)
noun
B)
adverb
C)
Interjection
D)
verb
Step-by-step analysis: 1. Identify the underlined word: In the sentence 'The greengrocer sells vegetable', the word 'greengrocer' (or 'vegetable', as both are nouns) is the target. In standard English grammar tests for this specific sentence, the focus is typically on the subject 'greengrocer' or the object 'vegetable'. 2. Define the part of speech: A noun is a word that functions as the name of a specific object or set of objects, such as living creatures, places, actions, qualities, states, concepts, or ideas. 3. Application: 'Greengrocer' refers to a person/profession, and 'vegetable' refers to a thing/food item. Both are nouns. 4. Evaluate options: (a) noun - Correct. (b) adverb - Incorrect, as it does not modify a verb, adjective, or other adverb. (c) Interjection - Incorrect, as it is not an abrupt remark or exclamation. (d) verb - Incorrect, as the verb in this sentence is 'sells'.
Choose the part of speech of the underlined word in the following sentence: 'Our final examinations are always held in December.'
A)
noun
B)
pronoun
C)
verb
D)
adverb
Step-by-step analysis of the sentence: 'Our final examinations are always held in December.'
1. Identify the underlined word: In this sentence, the word 'December' is the target word.
2. Analyze the function of 'December': 'December' is the name of a specific month of the year. In English grammar, names of specific people, places, or time periods (like months) are classified as Proper Nouns.
3. Contextual clue: The word follows the preposition 'in'. Prepositions are typically followed by a noun or a pronoun (the object of the preposition). In this case, 'December' serves as the object of the preposition 'in'.
Evaluating the options:
- (a) Noun: Correct. 'December' is a proper noun.
- (b) Pronoun: Incorrect. A pronoun replaces a noun (e.g., he, she, it). 'December' is the name itself, not a replacement.
- (c) Verb: Incorrect. A verb expresses an action or state of being (e.g., 'are held'). 'December' does not express an action.
- (d) Adverb: Incorrect. An adverb modifies a verb, adjective, or another adverb (e.g., 'always'). While 'December' provides time information, it functions as a noun here, not as a modifier of the verb.
Choose the tense of the verb in the following sentence: 'Your mother has been looking for you since morning.'
A)
Past perfect continuous tense
B)
Past perfect tense
C)
Present perfect tense
D)
Present perfect continuous tense
To identify the tense of the sentence 'Your mother has been looking for you since morning,' we analyze the verb phrase 'has been looking':
1. **'Has'**: This is the present tense of the auxiliary verb 'have', indicating the tense is in the Present category.
2. **'Been'**: This is the past participle of 'be', which is used to form perfect tenses.
3. **'Looking'**: This is the present participle (verb + -ing), which indicates a continuous or progressive action.
Combining these elements (Present Auxiliary + Been + Present Participle) forms the **Present Perfect Continuous Tense**. This tense is used to describe an action that started in the past and is still continuing in the present, often accompanied by a time reference (in this case, 'since morning').
Why other options are incorrect:
- **a. Past perfect continuous**: Would require 'had been looking'.
- **b. Past perfect**: Would require 'had looked'.
- **c. Present perfect**: Would require 'has looked' (without the 'been' and '-ing' form).
Choose the tense of the verb in the following sentence: 'She cuts her finger while cutting vegetables.'
A)
Present continuous tense
B)
Past continuous tense
C)
Present indefinite tense
D)
Past perfect tense
Step-by-step analysis of the sentence 'She cuts her finger while cutting vegetables':
1. **Identify the main verb**: The main verb in the sentence is 'cuts'.
2. **Analyze the verb form**: The verb 'cuts' is the base form of the verb 'cut' with the suffix '-s' added. This form is used specifically for third-person singular subjects (She) in the simple present tense.
3. **Determine the Tense**:
- **Present Indefinite (Simple Present)**: Used for habits, general truths, or repeated actions. The structure is [Subject + Verb(s/es)]. 'She cuts' fits this structure perfectly.
- **Present Continuous**: Would require 'is cutting' (Subject + is/am/are + verb-ing).
- **Past Continuous**: Would require 'was cutting' (Subject + was/were + verb-ing).
- **Past Perfect**: Would require 'had cut' (Subject + had + past participle).
4. **Address the phrase 'while cutting'**: The word 'cutting' here is a present participle acting as part of a subordinate clause (reduced adverbial clause), not the main finite verb of the sentence. The tense of the sentence is determined by the main verb 'cuts'.
Therefore, the correct tense is the Present Indefinite Tense.
Choose the correct antonym for: 'adversity'
A)
adjustment
B)
refinement
C)
duality
D)
prosperity
Step 1: Analyze the meaning of the target word. 'Adversity' refers to a state of misfortune, hardship, or difficult circumstances (e.g., poverty or bad luck).
Step 2: Evaluate the options to find the opposite meaning:
- (a) adjustment: The act of altering something to fit a new situation; not an antonym for hardship.
- (b) refinement: The process of removing impurities or improving something; not an antonym for hardship.
- (c) duality: The state of having two parts or elements; unrelated to hardship.
- (d) prosperity: The state of being successful, flourishing, or thriving, especially in financial terms. This is the direct opposite of misfortune and hardship.
Conclusion: Since 'adversity' represents a period of struggle and 'prosperity' represents a period of success and wealth, option (d) is the correct antonym.
Choose the part of speech of the underlined word in the following sentence: 'There is a little gravy left in the bowl.'
A)
adjective
B)
verb
C)
noun
D)
pronoun
In the sentence 'There is a little gravy left in the bowl,' the underlined word is 'little'. To determine its part of speech, we look at its function in the sentence: 'little' is modifying the noun 'gravy' by specifying the quantity of the gravy. Words that modify or describe nouns are classified as adjectives. Specifically, 'little' here acts as a quantitative adjective (or determiner).
Why other options are incorrect:
- b. verb: A verb expresses an action or state of being (e.g., 'is' in this sentence). 'Little' does not express an action.
- c. noun: A noun is a person, place, thing, or idea. 'Gravy' and 'bowl' are the nouns in this sentence; 'little' describes the noun rather than being one.
- d. pronoun: A pronoun replaces a noun (e.g., he, she, it). 'Little' is not replacing a noun but is modifying one.
Choose the tense of the verb in the following sentence: 'The cowherd had run a thorn into his foot.'
A)
Present indefinite tense
B)
Past perfect tense
C)
Present perfect tense
D)
Past indefinite tense
To determine the tense of the verb in the sentence 'The cowherd had run a thorn into his foot,' we analyze the verb phrase 'had run'.
1. Structure Analysis: The verb phrase consists of the auxiliary verb 'had' (the past tense of 'have') followed by the past participle 'run' (the forms of the verb are run-ran-run).
2. Tense Identification: The formula [had + past participle] is the definitive structure of the Past Perfect Tense. This tense is used to describe an action that was completed before another point in the past.
Evaluating the options:
- (a) Present indefinite tense: Requires the base form or -s/-es form of the verb (e.g., 'runs').
- (b) Past perfect tense: Matches the structure [had + past participle]. Correct.
- (c) Present perfect tense: Requires 'has' or 'have' + past participle (e.g., 'has run').
- (d) Past indefinite tense: Requires the simple past form of the verb (e.g., 'ran').
Choose the correct antonym for: 'Important'
A)
Imbibe
B)
incur
C)
trivial
D)
trident
Step 1: Analyze the target word. 'Important' means having great significance, value, or influence.
Step 2: Evaluate the options to find a word with the opposite meaning (antonym).
- Option (a) 'Imbibe' means to drink or absorb (liquid or ideas); it is unrelated to significance.
- Option (b) 'Incur' means to become subject to something unwelcome as a result of one's own behavior; it is unrelated to significance.
- Option (c) 'Trivial' means of little value or importance; insignificant. This is the direct opposite of 'important'.
- Option (d) 'Trident' is a three-pronged spear; it is a noun and unrelated to significance.
Step 3: Conclusion. Since 'trivial' describes something that lacks importance, it is the correct antonym.
Choose the correct synonym for: 'hamper'
A)
hint
B)
hinder
C)
temper
D)
candour
Step-by-step reasoning:
1. Analyze the target word: 'Hamper' as a verb means to hinder or impede the movement or progress of something; to obstruct.
2. Evaluate Option (a) 'hint': A hint is a slight indication or clue. It has no semantic relationship with obstruction.
3. Evaluate Option (b) 'hinder': To hinder means to create difficulties for someone or something, resulting in delay or obstruction. This is a direct synonym for 'hamper'.
4. Evaluate Option (c) 'temper': As a verb, temper means to serve as a neutralizing or moderating force; as a noun, it refers to a person's state of mind. It does not mean to obstruct.
5. Evaluate Option (d) 'candour': Candour refers to the quality of being open and honest in expression; frankness. It is unrelated to the meaning of 'hamper'.
Conclusion: 'Hinder' is the only word that matches the meaning of 'hamper'.
Choose the part of speech of the underlined word in the following sentence: 'India and Australia played in the final.'
A)
conjunction
B)
verb
C)
noun
D)
pronoun
Step-by-step analysis: 1. Identify the underlined word: In the sentence 'India and Australia played in the final', the word 'and' is the target word. 2. Analyze the function of 'and': The word 'and' is used to connect two words of the same grammatical category (the proper nouns 'India' and 'Australia'). 3. Define the part of speech: A word that joins words, phrases, or clauses is called a conjunction. Specifically, 'and' is a coordinating conjunction. 4. Evaluate other options: (b) 'verb' is incorrect because the verb in the sentence is 'played'. (c) 'noun' is incorrect because 'India' and 'Australia' are the nouns. (d) 'pronoun' is incorrect because 'and' does not replace a noun.
Choose the tense of the verb in the following sentence: 'Did you ever smoke in your life?'
A)
Past indefinite tense
B)
Past perfect tense
C)
Present indefinite tense
D)
Future indefinite tense
Step-by-step analysis: 1. Identify the verb structure: The sentence is an interrogative sentence starting with the auxiliary verb 'Did'. 2. Analyze the formula: In English grammar, the structure 'Did + subject + base form of verb' is the standard construction for the Past Indefinite Tense (also known as Simple Past Tense) in question form. 3. Evaluate the options: (a) Past Indefinite: Matches the 'Did' structure. (b) Past Perfect: Would require 'Had you ever smoked...'. (c) Present Indefinite: Would require 'Do you ever smoke...'. (d) Future Indefinite: Would require 'Will you ever smoke...'. Therefore, the use of 'Did' explicitly marks this as the Past Indefinite Tense.
Write a précis of the given passage regarding the requirements for writing clearly and logically, the nature of freedom and legal limitations, and the discipline required to be a successful writer.
Choose the tense of the verb in the following sentence: 'She will have finished her home-work by 4pm.'
A)
Future perfect tense
B)
Future perfect continuous tense
C)
Future indefinite tense
D)
Past perfect tense
Step-by-step analysis of the sentence 'She will have finished her home-work by 4pm':
1. **Identify the verb phrase**: The verb phrase is 'will have finished'.
2. **Analyze the structure**:
- 'will' indicates the future tense.
- 'have' is the auxiliary verb used for perfect aspects.
- 'finished' is the past participle of the verb 'finish'.
- The formula [will + have + past participle] is the standard construction for the Future Perfect Tense.
3. **Analyze the meaning**: The Future Perfect tense is used to describe an action that will be completed (perfected) at some point in the future before another action or a specific time (in this case, 'by 4pm').
**Why other options are incorrect:**
- **b. Future perfect continuous tense**: This would require the structure [will + have + been + verb-ing] (e.g., 'will have been finishing').
- **c. Future indefinite tense**: This would require the structure [will + base verb] (e.g., 'will finish').
- **d. Past perfect tense**: This would require the structure [had + past participle] (e.g., 'had finished').
Choose the correct antonym for: 'enrich'
A)
endorse
B)
cherish
C)
novelish
D)
impoverish
Step 1: Analyze the target word. 'Enrich' means to improve the quality or value of something, or to make someone wealthy.
Step 2: Evaluate the options to find the opposite meaning (antonym).
- Option (a) 'endorse' means to declare one's public approval or support of something; it is unrelated to wealth or quality improvement.
- Option (b) 'cherish' means to protect and care for someone or something lovingly; it is a positive emotion but not an antonym for enrich.
- Option (c) 'novelish' is a rare term referring to something resembling a novel; it is irrelevant to the context.
- Option (d) 'impoverish' means to make a person or area poor, or to exhaust the quality/strength of something. This is the direct opposite of 'enrich'.
Conclusion: Since 'enrich' is to make rich/better and 'impoverish' is to make poor/worse, option (d) is the correct antonym.
Choose the part of speech of the underlined word in the following sentence: 'River Ganga flows into the Bay of Bengal.'
A)
adjective
B)
Noun
C)
interjection
D)
preposition
Step-by-step reasoning: 1. Identify the underlined word: In the sentence 'River Ganga flows into the Bay of Bengal', the word 'River Ganga' (or 'Ganga') is the subject of the sentence. 2. Define the part of speech: A noun is a word that functions as the name of a specific object or set of objects, such as living creatures, places, actions, qualities, states of existence, or ideas. 3. Application: 'River Ganga' is the name of a specific geographical entity (a proper noun). 4. Evaluate options: (a) Adjective: It does not describe another noun; it is the noun itself. (b) Noun: Correct, as it names a specific river. (c) Interjection: It is not an exclamation expressing emotion. (d) Preposition: It does not show a relationship between a noun and another part of the sentence (the preposition in this sentence is 'into').
Choose the part of speech of the underlined word in the following sentence: 'A spider has many legs.'
A)
verb
B)
noun
C)
adjective
D)
pronoun
In the sentence 'A spider has many legs', the word 'legs' (which is the underlined word in this context) refers to a physical part of a body. By definition, a noun is a word that names a person, place, thing, or idea. Since 'legs' names a thing/body part, it functions as a noun.
Analysis of other options:
- a. verb: A verb expresses an action or state of being. In this sentence, 'has' is the verb.
- c. adjective: An adjective describes or modifies a noun. In this sentence, 'many' is the adjective modifying 'legs'.
- d. pronoun: A pronoun replaces a noun. There are no pronouns used in this specific sentence.
Choose the tense of the verb in the following sentence: 'The school shall remain close tomorrow'
A)
Present indefinite tense
B)
Future indefinite tense
C)
Future perfect tense
D)
Present perfect tense
Step-by-step analysis: 1. Identify the verb phrase: The verb phrase in the sentence is 'shall remain'. 2. Analyze the structure: The sentence uses the auxiliary verb 'shall' followed by the base form of the main verb 'remain'. 3. Determine the tense: In English grammar, the structure [will/shall + base verb] is used to denote the Future Indefinite (also known as Simple Future) tense. 4. Contextual clue: The word 'tomorrow' explicitly indicates a future time reference. 5. Evaluate options: (a) Present indefinite would be 'remains'; (c) Future perfect would be 'shall have remained'; (d) Present perfect would be 'has remained'. Therefore, 'shall remain' is the Future Indefinite tense.
Choose the correct antonym for: 'Coarse'
A)
soak
B)
damp
C)
fine
D)
poor
Step 1: Analyze the meaning of the target word. 'Coarse' refers to something that is rough in texture, consisting of large particles, or lacking refinement (e.g., coarse sand or coarse fabric).
Step 2: Evaluate the options to find the opposite meaning.
- (a) 'soak': To saturate with liquid; unrelated to texture.
- (b) 'damp': Slightly wet; unrelated to texture.
- (c) 'fine': In the context of texture or particles, 'fine' means consisting of very small particles or having a smooth, refined surface. This is the direct opposite of 'coarse'.
- (d) 'poor': Lacking quality or money; while 'coarse' can sometimes mean low quality, 'poor' is not its direct antonym in terms of physical properties.
Step 3: Conclusion. Since 'coarse' describes a rough/large-grained texture and 'fine' describes a smooth/small-grained texture, 'fine' is the correct antonym.
Write an essay on any one of the following topics: - Bamboo link roads as a measure to sustainable development in Mizoram - The socio-economic impact of Covid-19 pandemic and Lock down in Mizoram. - Tourism and the future aspect of Tourism in Mizoram