In electromagnetic spectrum, the frequencies of γ-rays and x-rays and ultraviolet rays are denoted by n₁,n₂ and n₃ respectively, then
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(a) n₁>n₂>n₃ (b) n₁n₃
Explanation:
Frequency range of ultraviolet rays ≃ 10¹⁶ […]
The ratio of magnetic dipole moment of an electron of charge e and mass m in Bohr’s orbit in hydrogen atom to its angular momentum is
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(a) e/m (b) m/e (c) 2m/e […]
In cyclotron, for a given magnet, radius of the semicircle traced by positive ion is directly proportional to (where, v=velocity of positive ion)
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(a) v⁻² (b) v⁻¹ (c) v (d) v²
Correct […]
Magnetic induction produced at the centre of a circular loop carrying current is B. The magnetic moment of the loop of radius R is (where, μ₀=permiability of free space)
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(a) BR²/2πμ₀ (b) […]
The equiconvex lens has focal length f. If it is cut perpendicular to the principal axis passing through optical centre, then focal length of each half is
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(a) f/2 (b) f (c) 3f/2 […]
In vacuum, to travel distance d, light takes time t and in medium to travel distance 5d, it takes time T. The critical angle of the medium is
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(a) sin⁻¹(5T/t) (b) sin⁻¹(5t/3T) (c) […]
Which of the following produces erythroprotein?
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(a) kidney (b) pancreas (c) Pineal gland (d) thyroid gland
Correct Answer:
kidney
Explanation:
No explanation available. Be the first to write the explanation for this […]
Two charges of equal magnitude q are placed in air at a distance 2a apart and third charge -2q is placed at mid-point. The potential energy of the system is (where, ε₀=permitivity of free space) […]
Two concentric spheres kept in air have radii R and r. They have similar charge and equal surface charge density σ. The electrical potential at their common centre is (where,ε₀=permitivity of free space)
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In common base circuit of a transistor, current amplification factor is 0.95. Calculate the emitter current, if base current is 0.2 mA.
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(a) 2 mA (b) 4 mA (c) 6 mA (d) […]
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