A coil 4.00 cm in radius, containing 500 turns, is placed in a uniform magnetic field that varies with time according to B = (0.0120 T/s)t + (3.00 x 10-5 T/s4)t4. The coil is connected to a 600 Ω resistor, and its plane is perpendicular to the magnetic field. You can ignore the resistance of the coil. What is the current in the resistor at time t = 5.00 s?

Respuesta :

Answer:

i = 1.13\times 10^{-4}A

Explanation:

r = radius of the coil = 4 cm = 0.04 m

Area of coil is given as

A = πr²

A = (3.14) (0.04)² = 0.005024 m²

N = Number of turns = 500

R = Resistance = 600 Ω

B = magnetic field = (0.0120)t + (3 x 10⁻⁵) t⁴

Taking derivative both side relative to "t"

[tex]\frac{dB}{dt}= (0.0120 + (12\times 10^{-5})t^{3})[/tex]

Induced current is given as

[tex]i = \left ( \frac{NA}{R} \right )\left ( \frac{dB}{dt} \right )[/tex]

[tex]i = \left ( \frac{NA}{R} \right ) (0.0120 + (12\times 10^{-5})t^{3})[/tex]

inserting the values at t = 5

[tex]i = \left ( \frac{(500)(0.005024)}{600} \right ) (0.0120 + (12\times 10^{-5})5^{3})[/tex]

[tex]i = 1.13\times 10^{-4}A[/tex]

Answer:

The current in the resistor is 1.1304 mA.

Explanation:

Given that,

Radius = 4.00 cm

Number of turns = 500

Magnetic field [tex]B=(0.0120)t+(3.00\times10^{-5})t^4[/tex]

Resistance [tex]R = 600\Omega[/tex]

Time t = 5.00 s

We need to calculate the emf

Using formula of emf

[tex]\epsilon=NA\dfrac{dB}{dt}[/tex]

Where, A = area

N = number of turns

B = magnetic field

Put the value into the formula

[tex]\epsilon = 500\times\pi\times(4.00\times10^{-2})^2\dfrac{d}{dt}((0.0120)t+(3.00\times10^{-5})t^4)[/tex]

[tex]\epsilon=500\times\pi\times(4.00\times10^{-2})^2\times(0.0120+1.2\times10^{-4})t^3[/tex]

We need to calculate the current in the resistor at t = 5.00

Using formula of current

[tex]\epsilon=IR[/tex]

[tex]I=\dfrac{\epsilon}{R}[/tex]

Where, R = resistance

Put the value into the formula

[tex]I=\dfrac{500\times\pi\times(4.00\times10^{-2})^2\times(0.0120+1.2\times10^{-4})t^3}{600}[/tex]

Put the value of t in equation (II)

[tex]I=\dfrac{500\times\pi\times(4.00\times10^{-2})^2\times(0.0120+1.2\times10^{-4})(5.00)^3}{600}[/tex]

[tex]I=0.00011304\ A[/tex]

[tex]I=1.1304\times10^{-3}\ A[/tex]

[tex]I=1.1304\ mA[/tex]

Hence, The current in the resistor is 1.1304 mA.