भौतिक विज्ञान (Physics) – Physics MCQ
भौतिक विज्ञान (Physics) – इन्जिनियरिङ प्रवेश
Physics · Engineering Entrance – Mathematics, Physics, Chemistry & English · १,३९८ प्रश्न
१,३९८ प्रश्न उपलब्ध। मोड छान्नुहोस्:
भौतिक विज्ञान (Physics): 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 long solenoid has 1000 turns per metre and carries a current of 2 A. The magnetic field inside it is about (μ₀ = 4π × 10⁻⁷ T m/A):
सही उत्तर: क) 2.5 × 10⁻³ T
B = μ₀nI = 4π × 10⁻⁷ × 1000 × 2 ≈ 2.51 × 10⁻³ T.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A galvanometer of resistance 50 Ω gives full-scale deflection at 10 mA. The shunt needed to convert it into an ammeter of range 1 A is about:
सही उत्तर: क) 0.505 Ω
S = G I_g/(I − I_g) = 50 × 0.01/0.99 ≈ 0.505 Ω.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A potentiometer wire 10 m long has a steady potential drop of 2 V across it. A cell is balanced at a length of 6 m. The emf of the cell is:
सही उत्तर: ख) 1.2 V
Potential gradient = 2/10 = 0.2 V/m, so E = 0.2 × 6 = 1.2 V.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
Two identical cells, each of emf 2 V and internal resistance 1 Ω, are connected in parallel across an external resistance of 1.5 Ω. The current in the external resistance is:
सही उत्तर: ग) 1 A
The parallel pair acts as emf 2 V with internal resistance 0.5 Ω, so I = 2/(1.5 + 0.5) = 1 A.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A wire 2 m long with cross-sectional area 1 mm² has a resistance of 0.034 Ω. The resistivity of its material is:
सही उत्तर: घ) 1.7 × 10⁻⁸ Ω m
ρ = RA/L = 0.034 × 10⁻⁶/2 = 1.7 × 10⁻⁸ Ω m.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The acceleration of an electron in a uniform electric field of 1000 V/m is about (e = 1.6 × 10⁻¹⁹ C, mₑ = 9.1 × 10⁻³¹ kg):
सही उत्तर: घ) 1.8 × 10¹⁴ m/s²
a = eE/m = 1.6 × 10⁻¹⁶/9.1 × 10⁻³¹ ≈ 1.76 × 10¹⁴ m/s².
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
Four equal charges q are placed at the corners of a square of side a. The electric potential at the centre of the square is (k = 1/4πε₀):
सही उत्तर: क) 4√2 kq/a
Each charge is at a distance a/√2 from the centre, so V = 4 × kq/(a/√2) = 4√2 kq/a.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The work done in bringing a charge of 2 μC from infinity to a point where the electric potential is 50 V is:
सही उत्तर: ख) 100 μJ
W = qV = 2 × 10⁻⁶ × 50 = 10⁻⁴ J = 100 μJ.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A parallel-plate air capacitor has plate area 0.02 m² and plate separation 1 mm. Its capacitance is about (ε₀ = 8.85 × 10⁻¹² F/m):
सही उत्तर: ग) 177 pF
C = ε₀A/d = 8.85 × 10⁻¹² × 0.02/10⁻³ ≈ 1.77 × 10⁻¹⁰ F = 177 pF.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The electric field at the centre of a uniformly charged circular ring is:
सही उत्तर: ग) zero
Contributions from diametrically opposite elements cancel, so the field at the centre is zero.
💬 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।