भौतिक विज्ञान (Physics) – Physics MCQ
भौतिक विज्ञान (Physics) – CEE प्रवेश
Physics · Medical Entrance (CEE) – Physics, Chemistry, Biology & MAT · ४०७ प्रश्न
४०७ 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
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A particle of mass m moves with velocity v in the x-direction. If its velocity is reversed and it moves with same magnitude then the change in momentum is: (Given: 1N=1 kg.m/s)
सही उत्तर: ख) mv
Momentum (p) = mv. When the velocity is reversed, the new velocity has the same magnitude but opposite direction. Therefore, the change in momentum is Δp = m(v_new - v_old) = m(-v - v) = -2mv. The correct answer is 2mv, and option 'mv' would be wrong because it doesn't account for the reversal of velocity.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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A uniform rod of length L is placed on a horizontal surface with one end in contact with a wall and the other end in contact with a fixed point. The coefficient of friction between the rod and the wall is μ. What is the maximum static friction force that can be exerted on the rod? (Given: g)
सही उत्तर: घ) 4μg
The maximum static friction force occurs when the rod is about to move. The frictional force resisting motion at the wall balances the component of weight acting perpendicular to the wall. This component is mgcosθ where θ is the angle with the wall. Therefore Ff = μmgcosθ ≈ 3μg . This makes 3μg the correct option, unlike options involving only 'm' or a smaller multiple of µg.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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A uniform conducting plate of length l and resistance R is bent into a circle. What is the radius of the circle?
सही उत्तर: ख) lπ
The circumference of the circle is 2πr, where r is the radius. Since the plate is bent into a circle with length l, we have 2πr = l. Therefore, r = l/(2π). The other options are incorrect because they do not reflect this relationship based on the geometry.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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A particle moves with a velocity v = (2t + t²) m/s, where 't' is in seconds. What is the displacement of the particle from its initial position after 2 seconds?
सही उत्तर: क) 10 m
Displacement is found by integrating the velocity function with respect to time. ∫v dt = ∫(2t + t²) dt = t² + (t³/3) + C. Since the particle starts at position 0 at t=0, C = 0. Therefore, displacement at t=2s is (2)² + ((2)³/3) = 4 + 8/3 = 12/3 + 8/3 = 20/3 ≈ 6.67m. The closest answer to this value is 6 m.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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A long solenoid has 700 turns and a length of 1 meter. If a current of 3 Amperes flows through it, what is the magnetic field strength (in Tesla) at its center?
सही उत्तर: क) 1.5 x 10⁻³ T
The magnetic field strength inside a solenoid is given by B = μ₀nI, where μ₀ (permeability of free space) = 4π × 10⁻⁷ T⋅m/A and n is the number of turns per unit length. In this case, n = 700 turns / 1 m = 700 turns/m and I = 3 A. Therefore, B = (4π × 10⁻⁷ T⋅m/A) * 700 * 3 A = 8.4 x 10⁻³ T. The closest answer is 3.0 x 10⁻³ T, which contains a rounding error.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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A uniform wire of length L is stretched until its diameter becomes D. If the Young's modulus for the material is Y, then the stress applied will be:
सही उत्तर: क) (a) LY/D
Stress is defined as force per unit area. In this case, the force applied is the stress, and the area is the cross-sectional area of the wire (πr² = π(D/2)²). So, Stress = Force / Area = Y * (D/2) / (D/2) = Y. Thus, it should be LY/D.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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The refractive index of a glass is 1.5 for light traveling in the direction of incidence and 1.3 for light travelling perpendicular to the direction of incidence. Calculate the ordinary and extraordinary refractive indices.
सही उत्तर: क) (a) Ordinary = 1.5, Extraordinary = 1.3
The ordinary refractive index (n₀) is the refractive index for light traveling perpendicular to the direction of incidence. The extraordinary refractive index (nₛ) is the refractive index for light traveling parallel to the direction of incidence. Given nᵢ = 1.5 and n⊥ = 1.3, we can find n₀ = 1.3 and nₛ = 1.5.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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A particle moving with velocity 'v' makes an angle θ with the normal to the plane of motion. The horizontal component of velocity is 2 m/s and the vertical component is 3 m/s, then what is the magnitude of the velocity?
सही उत्तर: क) (a) 3.5 m/s
The horizontal and vertical components of velocity are perpendicular to each other. Using the Pythagorean theorem, we can calculate the magnitude of the velocity: v = √( (2)² + (3)²) = √13 ≈ 3.6 m/s. The closest answer is (a) 3.5m/s.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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A beam of light is incident on a rectangular slab placed in front of a plane mirror. If the refractive index of the slab for light travelling parallel to its surface is 1.5, what will be the angle of deviation of the reflected ray from the normal? (a) 30° (b) 45° (c) 60° (d) 90°
सही उत्तर: क) (a) 30°
The angle of deviation is determined by the thickness and refractive index of the slab. When light passes through a rectangular slab, it bends at two angles – one when entering and one when exiting. The overall deviation is the difference between these two angles. In this case, with a refractive index of 1.5, the bending will be significant, leading to a larger deviation angle. Option (a) represents the most plausible value for the angle of deviation based on these principles.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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A particle moves with a constant velocity in a magnetic field. Which of the following statements is true about the force experienced by the particle?
सही उत्तर: ख) The force is perpendicular to both velocity and magnetic field
According to the Lorentz Force Law, a charged particle moving in a magnetic field experiences a force that is always perpendicular to both its velocity and the magnetic field. This makes option 1 correct. The other options misrepresent the relationship between the force and these variables.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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