Positive electric charge Q = 5.0 mu C is distributed uniformly through the volum
ID: 1418359 • Letter: P
Question
Positive electric charge Q = 5.0 mu C is distributed uniformly through the volume of a spherical insulator with radius of = 1.0 cm. Find the electric field inside and outside of the sphere. Assume the permittivity of insulator is the same as the permittivity of the free space. The resting potential difference across a cell membrane from outside to inside is initially at -90 mV. When a simulated is applied, Na^+ions are moved into the cell such that the potential changes to +20 mV for a short time. Assume the dielectric constant through the membrane is 4. If the membrane capacitance per unit area is 1 mu F/cm^2, how much charge moves through a membrane of area 0.05 cm^2? Find the membrane thickness. The charge on Na^+ is +e. How many ions move through the membrane? Find the total work that is needed to transport this amount sodium ions cross the membrane. The current through the 6.00 ohm resistor in the following circuit is 4.00 A, in the given direction. What are the currents through the 25.0 ohm and 20.0 ohm resistors?Explanation / Answer
3)
here 6 and 8 ohms are in parallel so, potential diffrence across them is same
8*I_8 = 6*4
==> I_8 = 24/8 = 3 A (current through 8 ohms)
current through 25 ohms, I_25 = 4 + 3
= 7 A <<<<<<<<<------------------Answer
potentail diffrence across upeer segment = 6*4 + 25*7
= 199 volts
so, potentail diffrence across 20 ohms = 199 volts
I_20*20 = 199
I_20 = 199/20
= 9.95 A <<<<<<<<<------------------Answer