A particle is dropped from a building. It takes 4 sec for the particle to reach the ground. Then height of the building is (g=10m/s²)
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(a) 20 m (b) 40 m (c) […]
A wheel has moment of inertia 5 x 10⁻³ kgm² and is making 20 revolutions per sec. The torque need to stop it in 10 sec is ___ x 10⁻²Nm
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(a) 2 […]
Two wires of the same dimensions but resistivities p1 and p2 are connected in series. The equivalent resistivity of the combination is
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(a) p1 + p2 (b) (p1 + p2) / 2 […]
The wavelength of the short radio waves, microwaves, ultraviolet waves are λ₁,λ₂ and λ₃ respectively. Arrange them in decreasing order.
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(a) λ₁,λ₂,λ₃ (b) λ₁,λ₃,λ₂ (c) λ₃,λ₂,λ₁ (d) λ₂,λ₁,λ₃
Correct Answer:
λ₁,λ₂,λ₃
Explanation: […]
A 1 µA beam of protons with a cross-sectional area of 0.5 sq.mm is moving with a velocity of 3 x 10⁴ m/s. The charge density of beam is
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(a) 6.6 x […]
The wave function (in SI unit) for a light wave is given as Ψ(x,t)= 10³ sin π(3×10⁶ x-9×10¹⁴ t) . The frequency of the wave is equal to
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(a) 4.5×10¹⁴ Hz (b) […]
A body rolls down a stair case of 5 steps. Each step has height 0.1 m and width 0.1 m. With what velocity will the body reach the bottom
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(a) 5√2 m/s […]
At what distance from the centre of earth, the value of acceleration due to gravity will be half that on the surface (R=radius of earth)
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(a) 2 R (b) R (c) 1.414 […]
A rocket with a lift-off mass 3.5 x 10⁴ kg is blasted upwards with an initial acceleration of 10 m/s². The initial thrust of the blast is
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(a) 1.75 x 10⁵ N […]
In an LCR series A.C circuit, the voltage across each of the components, L, C and R is 50V. The voltage across the L.C combination will be
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(a) 50 V (b) 50 […]
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