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प्रश्न
- A circular coil of 30 turns and radius 8.0 cm carrying a current of 6.0 A is suspended vertically in a uniform horizontal magnetic field of magnitude 1.0 T. The field lines make an angle of 60° with the normal of the coil. Calculate the magnitude of the counter torque that must be applied to prevent the coil from turning.
- Would your answer change, if the circular coil in (a) were replaced by a planar coil of some irregular shape that encloses the same area? (All other particulars are also unaltered.)
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उत्तर
(a) Number of turns on the circular coil, n = 30
Radius of the coil, r = 8.0 cm = 0.08 m
Area of the coil = πr2
= π(0.08)2
= 3.14 × 0.0064
= 0.0201 m2
Current flowing in the coil, I = 6.0 A
Magnetic field strength, B = 1 T
Angle between the field lines and normal with the coil surface,
θ = 60°
The coil experiences a torque in the magnetic field. Hence, it turns.
The counter torque applied to prevent the coil from turning is given by the relation,
τ = n IBA sin θ ...(i)
= 30 × 6 × 1 × 0.0201 × sin 60°
= `3.618 xx sqrt3/2`
= `3.618 xx 1.732/2`
= 3.618 × 0.866
= 3.133 N m
(b) It can be inferred from the relation (i) that the magnitude of the applied torque is not dependent on the shape of the coil. It depends on the area of the coil. Hence, the answer would not change if the circular coil in the above case is replaced by a planar coil of some irregular shape that encloses the same area.
संबंधित प्रश्न
The fraction of the total current passing through the galvanometer is ............ .
a) `S/(S+G)`
b) `G/(S+G)`
c) `(S+G)/G`
d) `(S+G)/S`
With the help of a neat and labelled diagram, explain the principle and working of a moving coil galvanometer ?
Write current sensitivity of a galvanomete S.I. unit.
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Outline the necessary steps to convert a galvanometer of resistance RG into an ammeter of a given range ?
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The current sensitivity of a galvanometer is defined as ______.
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When a current-carrying coil of N turns and area A, carrying current I, is placed in a magnetic field B, the magnitude of the magnetic torque acting on it is:
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