COMEDK2018PhysicsMagnetic Effects of Current
The resultant force on the current loop P Q R S due to a long current carrying conductor will be
Options
- A10⁻⁴ ~N
- B3.6 10⁻⁴ ~N
- C1.8 10⁻⁴ ~N
- D5 10⁻⁴ ~N
Correct answer
D. 5 10⁻⁴ ~N
Step-by-step solution
aligned I₁ &=20 ~A , I₂=20 ~A r₁ &=2 ~cm r₂ &=(10+2) cm =12 ~cm aligned The given situation is shown in the figure. The forces on arm S R and P Q are equal in magnitude and opposite in direction and also having same line of action, hence they cancel to each other. Resultant force on the current loop PQRS, aligned F &=F_ P S -F_ Q R &= ₀ 2 I₁ I₂ l r₁ - ₀ 2 I₁ I₂ l r₂ &= ₀ 2 I₁ I₂ l [ 1 r₁ - 1 r₂ ] =2 10⁻⁷ 20 20 15 10⁻² [ 1 2 10⁻² - 1 12 10⁻² ] =5 10⁻⁴ ~N aligned