पोखरा र पूर्वाञ्चल विश्वविद्यालय PU / PoU BE प्रवेश तयारी
पोखरा र पूर्वाञ्चल विश्वविद्यालय – PU / PoU BE प्रवेश
PU BE Entrance · Pokhara & Purbanchal University BE
३,८४१ प्रश्न उपलब्ध। मोड छान्नुहोस्:
BE/B.Arch प्रवेश: प्रश्न र उत्तर
सही लागेको विकल्पमा थिच्नुहोस्। सही भए हरियो, गलत भए रातो देखिन्छ; ३ सेकेन्डपछि सही उत्तर र व्याख्या देखिन्छ।
सही: ० / ०
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In amplitude modulation (AM), the property of the carrier wave that is varied according to the message signal is its:
सही उत्तर: क) amplitude
In AM the carrier amplitude varies with the instantaneous value of the modulating signal while the frequency stays constant.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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Sky waves used in long-distance short-wave radio communication are returned to the Earth by the:
सही उत्तर: ख) ionosphere
The ionised layers of the upper atmosphere reflect (refract back) radio waves of roughly 3–30 MHz.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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For a transistor to work as an amplifier (active region), its junctions must be biased as:
सही उत्तर: ग) emitter–base forward and collector–base reverse
In the active region the emitter injects carriers (forward bias) and the reverse-biased collector collects them.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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In an intrinsic semiconductor at room temperature, the number of free electrons (n) and holes (p) are related as:
सही उत्तर: ग) n = p
In a pure semiconductor each broken bond creates one electron–hole pair, so n = p = nᵢ.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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The de Broglie wavelength of a 1 kg ball moving at 1 m/s is about (h = 6.63 × 10⁻³⁴ J s):
सही उत्तर: घ) 6.63 × 10⁻³⁴ m
λ = h/(mv) = 6.63 × 10⁻³⁴/(1 × 1) m, far too small to observe.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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A very high temperature is required for nuclear fusion in order to:
सही उत्तर: क) give nuclei enough energy to overcome their Coulomb repulsion
Light nuclei must come within the range of nuclear forces, which requires overcoming the electrostatic barrier.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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In a nuclear reactor, cadmium or boron rods are used to:
सही उत्तर: ख) absorb neutrons and control the chain reaction
Cadmium and boron have large neutron-absorption cross-sections; inserting the rods reduces the neutron population.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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Nuclear forces are:
सही उत्तर: ख) short-ranged and nearly charge-independent
The strong nuclear force acts over about 1–3 fm and acts similarly between n–n, p–p and n–p pairs.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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Nuclei having the same mass number but different atomic numbers are called:
सही उत्तर: ग) isobars
Isobars (e.g. ⁴⁰Ar and ⁴⁰Ca) have the same A but different Z.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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The fraction of radioactive nuclei remaining undecayed after a time equal to two mean lives is about:
सही उत्तर: घ) 13.5%
N/N₀ = e^(−t/τ) = e⁻² ≈ 0.135.
💬 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।
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