प्राविधिक – इलेक्ट्रिकल, मेकानिकल र टेलिकम
प्राविधिक – इलेक्ट्रिकल, मेकानिकल र टेलिकम
Technical – Electrical, Mechanical & Telecom · ४,५०० प्रश्न
४,५०० प्रश्न उपलब्ध। मोड छान्नुहोस्:
इलेक्ट्रिकल र टेलिकम: प्रश्न र उत्तर
सही लागेको विकल्पमा थिच्नुहोस्। सही भए हरियो, गलत भए रातो देखिन्छ; ३ सेकेन्डपछि सही उत्तर र व्याख्या देखिन्छ।
सही: ० / ०
-
In a reaction-turbine installation, the draft tube is provided mainly to:
सही उत्तर: क) recover kinetic energy from the water leaving the runner and allow the turbine to be set above the tailrace
The diverging draft tube lowers the pressure at the runner exit, regaining most of the outlet velocity head and the height of the turbine above the tailwater.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The main purpose of a surge tank in a hydropower scheme is to:
सही उत्तर: ख) reduce water-hammer pressure in the penstock when the load changes suddenly
When the turbine gates close or open quickly, the surge tank absorbs or supplies water, limiting pressure surges (water hammer) in the penstock and tunnel.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A Francis (reaction) turbine is generally the most suitable choice for a hydropower site with:
सही उत्तर: ख) a medium head and medium discharge
Pelton wheels suit high heads, Kaplan turbines suit low heads; Francis turbines cover the wide medium-head range.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A hydropower plant uses a discharge of 2 m³/s under a net head of 100 m with an overall efficiency of 90%. Its electrical output (P = 9.81QHη kW) is about:
सही उत्तर: घ) 1.77 MW
P = 9.81 × 2 × 100 × 0.9 = 1765.8 kW ≈ 1.77 MW.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
Copper is preferred to aluminium for the windings of machines and transformers mainly because copper has:
सही उत्तर: ख) lower resistivity, so windings are smaller for the same resistance
Copper's lower resistivity and better mechanical strength allow more compact windings with lower losses.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
In a parallel RLC circuit at resonance, the power factor of the circuit is:
सही उत्तर: ग) unity
At resonance the inductive and capacitive susceptances cancel, so the circuit is purely resistive.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
In AC circuits, apparent power (the product of RMS voltage and RMS current) is expressed in:
सही उत्तर: घ) volt-amperes (VA)
Apparent power S = VI is measured in VA (or kVA); active power is in W and reactive power in VAR.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A capacitor connected across a DC supply stores energy in the form of:
सही उत्तर: क) the electric field in its dielectric
The stored energy ½CV² resides in the electric field between the plates.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A non-magnetic material such as air has a B–H curve that is:
सही उत्तर: क) a straight line through the origin
For air B = μ₀H with constant μ₀, so the curve is linear with no saturation or hysteresis.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
AC is preferred to DC for large-scale generation and distribution mainly because:
सही उत्तर: ख) AC voltage can be stepped up and down easily and efficiently with transformers
Transformers allow high-voltage transmission (low current, low I²R loss) and safe low-voltage utilisation.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
यी अभ्यास प्रश्न हुन्, आधिकारिक प्रश्न होइनन्। पाठ्यक्रम, विज्ञापन र नतिजाका लागि सम्बन्धित निकायको आधिकारिक वेबसाइट हेर्नुहोस्। उत्तरमा गल्ती भेटे प्रश्नमुनिको "टिप्पणी / गल्ती रिपोर्ट" मा लेख्नुहोस्।
नमस्ते! पाठ्यक्रम, सामान्य ज्ञान, भाषा परीक्षा वा कुनै प्रश्नको उत्तर बुझ्न सोध्नुहोस्।
AI ले गल्ती गर्न सक्छ। महत्वपूर्ण कुरा आधिकारिक स्रोतमा जाँच्नुहोस्।