A coil of resistance 100 Ω is placed in a magnetic field. If the magnetic flux φ linked with the coil varies with time t as φ=3 t2+2 t+4 The current in the coil at t=3 s is

Question

A coil of resistance 100 Ω is placed in a magnetic field. If the magnetic flux φ linked with the coil varies with time t as φ=3 t2+2 t+4 The current in the coil at t=3 s is (A) 0.20 A (B) 0.25 A (C) 0.15 A (D) 0.40 A

Tardigrade Admin · Accepted Answer

e=(d φ/d t)=6 t+2 ⇒ i=(e/R)=(6 t+2/100) =0.2 A at t=3 s

Q. A coil of resistance $100 Ω$ is placed in a magnetic field. If the magnetic flux $ϕ$ linked with the coil varies with time $t$ as $ϕ = 3 t^{2} + 2 t + 4$ The current in the coil at $t = 3 s$ is

0.20 A

0.25 A

0.15 A

0.40 A

$e = \frac{d ϕ}{d t} = 6 t + 2$
$\Rightarrow i = \frac{e}{R} = \frac{6 t + 2}{100}$
$= 0.2 A$ at $t = 3 s$

Q. A coil of resistance 100Ω is placed in a magnetic field. If the magnetic flux ϕ linked with the coil varies with time t as ϕ=3t2+2t+4 The current in the coil at t=3s is