A square loop of side 10 cm enters a magnetic field with 2 cm / s. The front edge enters the magnetic field at t=0, then which graph best depicts emf?

Question

A square loop of side 10 cm enters a magnetic field with 2 cm / s. The front edge enters the magnetic field at t=0, then which graph best depicts emf? (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

When square is completely inside the field

\Rightarrow

flux is constant

\Rightarrow e m f = 0

(for the time square is completely inside the field is i.e.

t = 5 sec

to

t = 20 sec

.)
For entering, emf will be opposite of that induced while coming out.
emf

= B V ℓ = (1.2) (\frac{2}{100}) (\frac{10}{100})

= 2.4 \times 1 0^{- 3}

Volt

Q. A square loop of side 10cm enters a magnetic field with 2cm/s. The front edge enters the magnetic field at t=0, then which graph best depicts emf?

When square is completely inside the field ⇒ flux is constant ⇒emf=0 (for the time square is completely inside the field is i.e. t=5sec to t=20sec.) For entering, emf will be opposite of that induced while coming out. emf =BVℓ=(1.2)(1002​)(10010​) =2.4×10−3 Volt

Q. A square loop of side $10 c m$ enters a magnetic field with $2 c m / s$ . The front edge enters the magnetic field at $t = 0$ , then which graph best depicts emf?