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
-
From the same AC supply, a resistor branch draws 3 A and a pure inductor branch connected in parallel draws 4 A. The total supply current is:
सही उत्तर: क) 5 A
The branch currents are 90 degrees apart, so I = sqrt(3^2 + 4^2) = 5 A.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
Two 50 Hz sinusoidal voltages differ in phase by 90 degrees. The time between their positive peaks is:
सही उत्तर: ग) 5 ms
One cycle lasts 20 ms (360 degrees), so 90 degrees corresponds to 20 / 4 = 5 ms.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A coil of 100 turns and area 0.01 m^2 rotates at 100 rad/s in a uniform magnetic field of 0.1 T. The peak emf induced is:
सही उत्तर: ग) 10 V
E_m = N B A omega = 100 x 0.1 x 0.01 x 100 = 10 V.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
In circuits with magnetically coupled coils, the dot convention is used to show:
सही उत्तर: क) The relative polarity of the mutually induced voltages
Current entering a dotted terminal induces a voltage that is positive at the dotted terminal of the other coil.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A coil of 100 turns carrying 4 A produces a flux of 2 mWb linking all its turns. Its self-inductance is:
सही उत्तर: ख) 0.05 H
L = N phi / I = 100 x 0.002 / 4 = 0.05 H.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
If the thickness of the laminations in a transformer core is halved (all else unchanged), the eddy current loss becomes:
सही उत्तर: घ) One quarter of its original value
Eddy current loss is proportional to the square of lamination thickness, so halving thickness gives (1/2)^2 = 1/4.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
In the analogy between magnetic and electric circuits, magnetic flux corresponds to:
सही उत्तर: घ) Electric current
Flux = mmf / reluctance mirrors current = emf / resistance, so flux is the analogue of current.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
Permeance, the reciprocal of reluctance, is measured in:
सही उत्तर: ख) Weber per ampere-turn
Permeance = flux / mmf, so its unit is Wb/AT (dimensionally the henry).
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
An iron ring has a mean length of 1 m, a cross-section of 10^-3 m^2 and relative permeability 1000. Its reluctance is about:
सही उत्तर: ग) 7.96 x 10^5 AT/Wb
S = l / (mu_0 mu_r A) = 1 / (4 pi x 10^-7 x 1000 x 10^-3) = 1 / (1.257 x 10^-6) = about 7.96 x 10^5 AT/Wb.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
An electromagnet pole face of area 0.01 m^2 has a flux density of 1 T across the air gap. Using F = B^2 A / (2 mu_0), the lifting force is about:
सही उत्तर: क) 3.98 kN
F = 1^2 x 0.01 / (2 x 4 pi x 10^-7) = 0.01 / (2.513 x 10^-6) = about 3979 N.
💬 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।