Answer:
12500 V
Explanation:
The electric field in the gap of a parallel-plate capacitor is uniform, so the following relationship between electric field strength, potential difference and distance can be used:

where
is the potential difference between the plates
E is the electric field strength
d is the distance between the plates
For the capacitor in this problem, we have


Substituting, we find

A moment causes a rotation about or axis. If the moment is to be taken about a point due to a force F, then in order for a moment to develop, the line of action cannot pass through that point...... the total moment was zero because the moment arm was zero as well
Answer:
the question is incomplete, the complete question is
"A circular coil of radius r = 5 cm and resistance R = 0.2 ? is placed in a uniform magnetic field perpendicular to the plane of the coil. The magnitude of the field changes with time according to B = 0.5 e^-t T. What is the magnitude of the current induced in the coil at the time t = 2 s?"
2.6mA
Explanation:
we need to determine the emf induced in the coil and y applying ohm's law we determine the current induced.
using the formula be low,

where B is the magnitude of the field and A is the area of the circular coil.
First, let determine the area using
where r is the radius of 5cm or 0.05m

since we no that the angle is at
we determine the magnitude of the magnetic filed


the Magnitude of the voltage is 0.000532V
Next we determine the current using ohm's law


Answer:
some common devices that use current carrying conductors and magnetic fields are electric motor electric generator loudspeakers microphones and measuring instruments like galvanometer ammeter and voltmeter
Answer:
R = 6.8
Explanation:
Given data:
Richter scale
where R - magnitude of earthquake of Richter scale
I - quake's intensity 
- minimum intensity earthquake
Plugging all information in the equation to get Richter's scale


R = 6.8