Flux $\mathrm{\varphi }$ (in weber) in a closed-circuit of resistance 10 ohm varies with time t (in sec) according to the equation :

                                                                    $\mathrm{\varphi }= 6{\mathrm{t}}^2-5\mathrm{t}+1$

What is the magnitude of the induced current at t = 0.25 s ?

• A

  1.2 A

• B

  0.8 A

• C

  0.6 A

• D

  0.2 A