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JEE Mains · Physics · STD 12 - 4. Moving charges and magnetism
Bob of a simple pendulum of length \(l\) is made of iron . The pendulum is oscillating over a horizontal coil carrying direct current. If the time period of the pendulum is \(T\) then
- A \(T < 2\pi \sqrt {\frac{l}{g}} \) and damping is smaller than in air alone.
- B \(T = 2\pi \sqrt {\frac{l}{g}} \) and damping is larger than in air alone.
- C \(T > 2\pi \sqrt {\frac{l}{g}}\) and damping is smaller than in air alone.
- D \(T < 2\pi \sqrt {\frac{l}{g}} \) and damping is larger than in air alone
Answer & Solution
Correct Answer
(D) \(T < 2\pi \sqrt {\frac{l}{g}} \) and damping is larger than in air alone
Step-by-step Solution
Detailed explanation
When the pendulum is oscillating over a current carrying coil , and when the direction of oscillating pendulum bob is opposite to the direction of current. Its instantaneous acceleration increases. Hence time period \(T < 2\pi \sqrt {\frac{\ell }{g}} \) and damping is larger…
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