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JEE Mains 2020 physics questions with solutions
Browse JEE Mains 2020 Physics questions with solutions. Useful for JEE, NEET, and school exam revision.
Showing 1–10 of 54 questions
- MCQmediumElectromagnetic Induction
At time t = 0 magnetic field of 1000 Gauss is passing perpendicularly through the area defined by the closed loop shown in the figure. If the magnetic field reduces linearly to 500 Gauss, in the next 5s, then induced EMF in the loop is : 16cm 2cm 4cm
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Open question & full solution → - MCQmediumFluid Mechanics
Two liquids of densities ρ₁ an ρ₂ (ρ₂ = 2ρ₁) are filled up behind a square wall of side 10 m as shown in figure. Each liquid has a height of 5 m. The ratio of the forces due to these liquids exerted on upper part MN to that at the lower part NO is (Assume that the liquids are not mixing). Image
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Open question & full solution → - MCQmediumCurrent electricity
A galvanometer is used in laboratory for detecting the null point in electrical experiments. If, on passing a current of 6mA it produces a deflection of 2°, its figure of merit is close to :
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Open question & full solution → - MCQmediumGeometrical optics
If we need a magnification of 375 from a compound microscope of tube length 150 mm and an objective of focal length 5 mm, the focal length of the eye-piece, should be close to:
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Open question & full solution → - MCQmediumElectrostatic
Two isolated conducting spheres S₁ and S₂ have radii r₁ = 2R/3 and r₂ = R/3. They initially carry charges q₁ = +12 μC and q₂ = -3 μC, respectively, and are very far apart. They are connected by a conducting wire. After electrostatic equilibrium is reached, the charges on S₁ and S₂ are:
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Open question & full solution → - MCQeasyWave Motion
Two coherent sources of sound, S₁ and S₂, produce sound waves of the same wavelength, λ = 1 m, in phase. S₁ and S₂ are placed 1.5 m apart (see fig.) A listener, located at L, directly in front of S₂ finds that the intensity is at a minimum when he is 2m away from S₂. The listener moves away from S₁, keeping his distance from S₂ fixed. The adjacent maximum of intensity is observed when the listener is at a distance d from S₁. Then, d is:
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Open question & full solution → - MCQmediumMagnetic effect of current
A perfectly dimagnetic sphere has a small spherical cavity at its centre, which is filled with a paramagnetic substance. The whole system is placed in a uniform magnetic field B⃗ . Then the field inside the paramagnetic substance is:
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Open question & full solution → - MCQmediumUnit dimension and error
A physical quantity z depends on a, b, c, d as z = a²b²ᐟ³/(√c·d³). The percentage errors in a, b, c, d are 2%, 1.5%, 4% and 2.5%, respectively. Find the percentage error in z.
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Open question & full solution → - MCQmediumAC Circuits
A 750 Hz, 20 V (rms) source is connected to a resistance of 100 Ω, an inductance of 0.1803 H and a capacitance of 10 μF, all in series. The time in which the resistance (heat capacity 2J/°C) will get heated by 10°C. (Assume no loss of heat to the surroundings) is close to :
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Open question & full solution → - MCQmediumGeometrical optics
In a compound microscope, the magnified virtual image is formed at a distance of 25 cm from the eye-piece. The focal length of its objective lens is 1 cm. If the magnification is 100 and the tube length of the microscope is 20 cm, then the focal length of the eye-piece lens (in cm) is __________.
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