Answer:
55 mA
Explanation:
Ohm's law states:
V = IR
where V is voltage, I is current, and R is resistance.
220 V = I (4000 Ω)
I = 0.055 A
I = 55 mA
Answer:

Explanation:
Given;
The operational pressure of the cooker, 
area of the opening, 
- We know that the gauge pressure is measured with respect to the atmospheric pressure. As the atmospheric pressure acts on all the components of the system being observed so, we only need to counter the gauge pressure.
As the petcock sits on the opening of the cross-section so, it balances the built-in pressure due to its weight.
<u>Hence:</u>

where:
mass of the petcock
acceleration due to gravity


Answer:
A. Ein = 8.05*10^-4 V/m
B. Clockwise sense
Explanation:
A. the magnitude of the electric field induced in the ring is obtaind by using the following formula:
(1)
Ein: induced electric field
ds: differential of a path of the ring
ФB: magnetic flux in the ring
The Ein vector is parallel to ds in the complete ring. Furthermore, the area of the ring is constant, hence, you have in the equation (1):
(2)
dB/dt = -0.280T/s (it is decreasing)
A: area of the ring = π(r/2)^2= (π/4) r^2
r: radius of the ring = 4.60/2 = 2.30 cm
Then, you replace the values of all variables in the equation (2):

hence, the induced electric field is 8.05*10^-4 V/m
B. The induced current in the ring produced a magnetic field that is opposite to the magnetic field of the magnet. The, in this case you have that the induced current is in a clockwise sense.
Night hunting animals have more rod cells in their retinas which allows them to see better in the dark.