Magnetic Fields due to Electric Current
Magnetic Fields due to Electric Current
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See all →- A circular coil of 100 turns and radius 10 cm carries a current of 5 A. The magnetic field at its centre is (\(\mu_0=4\pi\times10^{-7}\) T m/A) Answer: D. π×10⁻³ T B=μ₀NI/2R=frac4π×10⁻⁷×100×50.2=π×10⁻³ T. 1
- A proton and an α-particle having the same kinetic energy enter a uniform magnetic field perpendicular to it. The ratio of the radii of their circular paths \(r_p:r_\alpha\) is Answer: A. 1 : 1 r=√(2mK)/qB . For α: mass 4m , charge 2e gives √(8mK)/2eB=√(2mK)/eB , same as proton. 1
- A rectangular coil of 50 turns and area 0.02 m2 carries 2 A in a uniform field of 0.5 T. The torque on it when its plane is parallel to the field is Answer: B. 1 N m Plane parallel to field means the normal is perpendicular to B : τ=NIAB=50×2×0.02×0.5=1 N m. 1
- A piece of straight wire has mass 20 g and length 1m. It is to be levitated using a current of 1 A flowing through Data: m = 20 g = 2 × 10⁻² kg, l = 1 m, I = 1 A, g = 9.8 m/s² To balance the wire, the upward magnetic force must be equal in magnitude to th... 1
- Calculate the value of magnetic field at a distance of 2 cm from a very long straight wire Data : I = 5A, a = 0.02 m, fracμ₀4 π = 10⁻⁷ T∙m/A The magnetic induction, B = fracμ₀ I2 π a=fracμ₀4 π 2 I/a = 10⁻⁷ × frac2(5)2 × 10⁻² = 5 ×... 1
- Two wires shown in the figure are connected in a series circuit and the same amount of current of 10 A Data: I₁ = I₂ = 10 A, s = 8 mm = 8 × 10⁻³ m, l = 0.22 m By right hand grip rule, the direction of the magnetic field overrightarrowB₂ due to... 1