UPPSC AE Mechanical flashcards
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32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Carnot efficiency formula
- For a reversible engine operating between hot reservoir T_H and cold reservoir T_L (absolute temperatures), efficiency equals 1 − T_L/T_H. No engine working between the same two reservoirs can be more efficient.
- Otto cycle efficiency
- Efficiency of the ideal constant-volume air cycle is 1 − r^(1−γ), where r is the compression ratio and γ the specific heat ratio. Higher compression ratio raises efficiency, limited by knock.
- Euler buckling load
- The critical axial load for a long slender column is P_cr = π²EI/L_e², where E is Young's modulus, I the least second moment of area and L_e the effective length.
- Maximum shear in rectangular beam
- For a rectangular cross-section, the maximum transverse shear stress occurs at the neutral axis and equals 1.5 times the average shear stress, that is 1.5 V/A.
- Shaft torsion formula
- For a solid circular shaft of diameter d under torque T, maximum shear stress is 16T/(πd³). Angle of twist over length L is TL/(GJ) with J = πd⁴/32.
- Reynolds number meaning
- Re = ρVD/μ compares inertia to viscous forces. In pipe flow, Re below about 2000 indicates laminar flow, 2000–4000 transitional, and above 4000 turbulent flow.
- Pelton wheel bucket speed
- A Pelton turbine extracts maximum energy when bucket speed u equals half the jet velocity V, giving zero exit whirl. It suits high heads and low discharge.
- Volumetric efficiency of compressor
- The ratio of actual delivered volume to swept volume of a reciprocating compressor. It decreases as clearance volume and pressure ratio increase because of re-expansion of trapped gas.
- Grashof condition
- A four-bar linkage has at least one fully rotating link when the sum of shortest and longest links is less than or equal to the sum of the other two links.
- Cavitation in pumps
- Formation and collapse of vapour bubbles when local pressure drops below vapour pressure. It causes noise, vibration, erosion and loss of head; remedy is adequate net positive suction head.
- Joule–Thomson coefficient
- Defined as μ = (∂T/∂P)_h. It is positive below the inversion temperature, so throttling cools the fluid; it is zero at the inversion point and negative above it.
- Constitution adoption date
- The Constitution of India was adopted by the Constituent Assembly on 26 November 1949 and came into force on 26 January 1950, the date now observed as Republic Day.
- Article 32 significance
- Article 32 guarantees the right to move the Supreme Court for enforcement of Fundamental Rights. Dr Ambedkar described it as the heart and soul of the Constitution.
- Directive Principles location
- Part IV of the Constitution, Articles 36 to 51, contains the Directive Principles of State Policy. They are not enforceable in courts but guide state policy making.
- Fundamental Duties amendment
- Fundamental Duties were inserted by the 42nd Constitutional Amendment Act of 1976 on the recommendation of the Swaran Singh Committee and placed in Part IVA, Article 51A.
- Tropic of Cancer states
- The Tropic of Cancer passes through eight Indian states: Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal, Tripura and Mizoram.
- Money Bill provision
- A Money Bill can be introduced only in the Lok Sabha on the President's recommendation. The Rajya Sabha may keep it for at most 14 days and cannot amend it.
- NITI Aayog establishment
- NITI Aayog replaced the Planning Commission on 1 January 2015. It is a policy think tank chaired by the Prime Minister and publishes indices such as the SDG India Index.
- Uttar Pradesh geography
- Uttar Pradesh is India's most populous state, with Lucknow as capital. It shares borders with eight states and Nepal and is drained by the Ganga and Yamuna.
- दीर्घ संधि
- जब ह्रस्व या दीर्घ अ, इ, उ के बाद समान स्वर आता है तो दोनों मिलकर दीर्घ हो जाते हैं। उदाहरण: विद्या + आलय = विद्यालय, हिम + आलय = हिमालय।
- बहुव्रीहि समास
- जिस समास में कोई भी पद प्रधान न होकर दोनों मिलकर किसी तीसरे अर्थ का बोध कराएँ, वह बहुव्रीहि है। उदाहरण: दशानन, चक्रधर, नीलकंठ।
- अनुप्रास अलंकार
- जहाँ एक ही वर्ण की आवृत्ति एक से अधिक बार होती है, वहाँ अनुप्रास अलंकार होता है। उदाहरण: चारु चंद्र की चंचल किरणें।
- शांत रस
- निर्वेद, वैराग्य और मोक्ष की प्रधानता वाला रस शांत रस कहलाता है; इसका स्थायी भाव निर्वेद है और इसे रसराज माना जाता है।
- कर्म कारक
- जिस पर क्रिया का प्रभाव पड़े, वह कर्म कारक होता है। इसका विभक्ति चिह्न 'को' है, जैसे राम ने पत्र को पढ़ा।
- मुहावरा: अंधे की लाठी
- इस मुहावरे का अर्थ है एकमात्र सहारा या अकेला समर्थन। जैसे वृद्ध पिता के लिए उनका पुत्र अंधे की लाठी है।
- उत्कर्ष का विलोम
- उत्कर्ष का विलोम शब्द अपकर्ष है। उत्कर्ष का अर्थ उन्नति या बढ़ोतरी और अपकर्ष का अर्थ अवनति या गिरावट होता है।
- Subject-verb agreement rule
- Singular subjects take singular verbs, but indefinite pronouns such as each, either, neither and everyone are singular. Collective nouns take a singular verb when acting as one unit.
- Present perfect tense use
- Formed with has or have plus the past participle, it expresses a past action linked to the present, an action of unfinished time, or experience without a stated past time.
- Since versus for
- Use 'since' with a point of time when the action began, as in since 2010, and 'for' with a length of time, as in for five years. Both suit perfect tenses.
- Between versus among
- Use 'between' for two distinct persons or things and for pairwise relations, and 'among' for more than two considered as a group without individual pairing.
- Passive voice formation
- The object becomes the subject, the verb becomes a form of be plus the past participle, and the original subject follows 'by'. Only transitive verbs take the passive.
- Idiom: blessing in disguise
- The phrase describes an apparent misfortune that eventually proves beneficial. Example: losing that job was a blessing in disguise because it led to a better career.