An elastic circular conducting loop expands at a constant rate in time. The radius is initially 0.200 m. but then begins to increase 0.018 m every second. The loop has a constant resistance of 15 Ohm and Is placed in a region of uniform (same everywhere) magnetic field of 0.880 T, perpendicular to the plane of the loop. Calculate the magnitude of the Induced curt 2.4 s after the loop begins expanding.

4.5 mA

Explanation:

Parameters given:

Initial radius of coil = 0.2 m

Rate of expansion of coil = 0.018 m/s

Resistance, R = 15 ohms

Magnetic field, B = 0.88 T

Time taken to expand, t = 2.4 s

To find the induced current, we have to first find the induced EMF. This can be gotten by using the formula below:

where A = area of coil

To find the area, we need to find the radius of the coil 2.4 seconds after it started expanding.

After 2.4s, the coil had expanded to become:

r = 0.2 + (0.018 * 2.4) = 0.2 + 0.0432 = 0.2432 m

Area = =

The magnitude of the Voltage induced will be:

From Ohm's law, we have that:

=>

The magnitude of the Induced curt 2.4 s after the loop begins expanding is 4.5 mA

it has to be b, about 97 percent.

i had this question and the answer was 3.15 miles.

martina travels from school to her mom's office. from there, she walks to school. after school, she walks to the library and then to a friends house before finally ending back at home. find martina's total distance traveled.

a) 0 miles  

b) 0.4 miles  

c) 1 mile  

d) 3.15 miles