इन्जिनियरिङ प्रवेश – Mathematics, Physics, Chemistry, English
इन्जिनियरिङ प्रवेश – Mathematics, Physics, Chemistry, English
Engineering Entrance – Mathematics, Physics, Chemistry & English · ३,८४१ प्रश्न
३,८४१ प्रश्न उपलब्ध। मोड छान्नुहोस्:
इन्जिनियरिङ 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
-
Three charges of +1 μC each are at the corners of an equilateral triangle of side 1 m. The magnitude of the net force on any one of them is about (1/4πε₀ = 9 × 10⁹ N m²/C²):
सही उत्तर: घ) 1.56 × 10⁻² N
Each pair force is 9 × 10⁻³ N and the two forces are at 60°: F = 2F₀cos 30° = √3 × 9 × 10⁻³ ≈ 1.56 × 10⁻² N.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A compound microscope has objective focal length 1 cm and eyepiece focal length 5 cm, with a tube length of 15 cm. Its approximate magnifying power for final image at infinity is (D = 25 cm):
सही उत्तर: ग) 75
M ≈ (L/fₒ)(D/fₑ) = (15/1)(25/5) = 75.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A convex lens and a concave lens, each of focal length 25 cm in magnitude, are placed in contact. The combination behaves as:
सही उत्तर: ग) a plane glass plate of zero power
P = 1/f₁ + 1/f₂ = 4 D − 4 D = 0, so the focal length is infinite: the pair acts like a plane plate.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
In Young's experiment with λ = 600 nm, a thin glass sheet (n = 1.5) of thickness 6 μm is placed over one slit. The central fringe shifts by:
सही उत्तर: क) 5 fringe widths
Number of fringes shifted = (n − 1)t/λ = 0.5 × 6 × 10⁻⁶/(6 × 10⁻⁷) = 5.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
In Young's double-slit experiment the maximum intensity is I₀. At a point where the path difference is λ/3, the intensity is:
सही उत्तर: घ) I₀/4
Phase difference φ = 2π/3, and I = I₀cos²(φ/2) = I₀cos²60° = I₀/4.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A glass slab 12 cm thick (n = 1.5) is placed over a mark on paper. Viewed from above, the mark appears raised by:
सही उत्तर: ख) 4 cm
Normal shift = t(1 − 1/n) = 12(1 − 2/3) = 4 cm.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
In the displacement method, the screen is 100 cm from the object and the two lens positions giving sharp images are 20 cm apart. The focal length of the lens is:
सही उत्तर: क) 24 cm
f = (D² − d²)/(4D) = (10000 − 400)/400 = 24 cm.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A convex lens forms a real image twice the size of the object on a screen 90 cm from the object. The focal length of the lens is:
सही उत्तर: ख) 20 cm
u + v = 90 with v = 2u gives u = 30 cm and v = 60 cm; 1/f = 1/30 + 1/60 = 1/20, so f = 20 cm.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A biconvex lens (n = 1.5) has radii of curvature 10 cm and 15 cm. Its focal length in air is:
सही उत्तर: ग) 12 cm
1/f = (n − 1)(1/R₁ − 1/R₂) = 0.5(1/10 + 1/15) = 0.5 × 1/6 = 1/12, so f = 12 cm.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A concave mirror of focal length 20 cm forms a real image 60 cm in front of it. The object distance is:
सही उत्तर: घ) 30 cm
1/u = 1/f − 1/v = 1/20 − 1/60 = 2/60, so u = 30 cm (in front of the mirror).
💬 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।