A150 turn circular coil has diameter of 5.25cm and is connected to a load with resistance of 10 ohms. a magnetic field perpendicular to the coil is changing at a rate of 1.0 t/s. a) calculate the magnitude of the emf.
b) calculate the magnitude of the induced current flowing through the load.
c) what is the value of the current if a second resistor of 20 ohms is connected in series with the first one?

(a) 0.325 V

(b) 0.0325 A

(c) 0.011 A

Explanation:

N = 150

diameter = 5.25 cm

radius, r = diameter / 2 = 2.625 cm = 0.02625 m

R = 10 ohm

dB / dt = 1 T/s

(a) Let e be the magnitude of induced emf

e = rate of change of magnetic flux

e = dФ / dt

e = N x A x dB / dt

e = 150 x 3.14 x 0.02625 x 0.02625 x 1 = 0.325 V

(b) induced current , i = induced emf / R = 0.325 / 10 = 0.0325 A

(c) When 10 ohm is connected in series with 20 ohm, then equivalent resistance is 10 + 20 = 30 ohm

induced current, i = 0.325 / 30 = 0.011 A

wavelength divides in half and speed stays the same.

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =