आधारभूत विद्युत् (Basic Electrical) – Basic Electrical Engineering MCQ
आधारभूत विद्युत् (Basic Electrical) – इलेक्ट्रिकल र टेलिकम
Basic Electrical Engineering · Technical – Electrical, Mechanical & Telecom · २,२९९ प्रश्न
२,२९९ प्रश्न उपलब्ध। मोड छान्नुहोस्:
आधारभूत विद्युत् (Basic Electrical): प्रश्न र उत्तर
सही लागेको विकल्पमा थिच्नुहोस्। सही भए हरियो, गलत भए रातो देखिन्छ; ३ सेकेन्डपछि सही उत्तर र व्याख्या देखिन्छ।
सही: ० / ०
-
A 4-pole, 50 Hz induction motor runs at 1440 rpm. Its slip is:
सही उत्तर: घ) 4%
Ns = 1500 rpm; slip = (1500 - 1440) / 1500 = 60 / 1500 = 0.04 = 4%.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The synchronous speed of a 4-pole induction motor supplied at 50 Hz is:
सही उत्तर: ख) 1500 rpm
Ns = 120 f / P = 120 x 50 / 4 = 1500 rpm.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
Which transformer loss remains practically constant from no load to full load?
सही उत्तर: ग) Core (iron) loss
Core loss depends on voltage and frequency, which stay constant, so it is essentially independent of load.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The copper loss of a transformer varies:
सही उत्तर: क) with the square of the load current
Copper loss = I^2 R in the windings, so it is proportional to the square of the load current.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
Hysteresis loss in a transformer core is reduced by making the core of:
सही उत्तर: घ) silicon steel
Silicon steel has a narrow hysteresis loop, so less energy is lost per magnetisation cycle.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The core of a transformer is made of thin laminations mainly to reduce:
सही उत्तर: क) eddy-current losses
Thin insulated laminations break up eddy-current paths, reducing eddy-current loss.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
An ideal 2200/220 V step-down transformer supplies a secondary current of 50 A. The primary current is:
सही उत्तर: क) 5 A
I1 / I2 = V2 / V1 = 1/10, so I1 = 50 / 10 = 5 A.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
An ideal transformer has 200 primary turns and 1000 secondary turns. If the primary is supplied at 230 V, the secondary voltage is:
सही उत्तर: ख) 1150 V
V2 = V1 x N2 / N1 = 230 x 1000 / 200 = 1150 V.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A transformer is not operated on a DC supply mainly because:
सही उत्तर: ग) DC produces no changing flux, so no emf is induced in the secondary
Without changing flux there is no induced emf; the primary, having only low winding resistance, would also draw a heavy current and burn.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A transformer works on the principle of:
सही उत्तर: ग) mutual induction
An alternating flux produced by the primary links the secondary and induces an emf in it (mutual induction).
💬 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।