The electromotive force (∈) = 2 V
<h3>Further explanation</h3>
Given
I=2 A
t = 30 s
E = 120 J
Required
The electromotive force (∈)
Solution
The electromotive force : the potential difference between two electrodes in galvanic cell
Can be formulated :

E = energy, J
Q = charge , Coulomb = i.t

Complete Question
An electron is accelerated by a 5.9 kV potential difference. das (sd38882) – Homework #9 – yu – (44120) 3 The charge on an electron is 1.60218 × 10−19 C and its mass is 9.10939 × 10−31 kg. How strong a magnetic field must be experienced by the electron if its path is a circle of radius 5.4 cm?
Answer:
The magnetic field strength is 
Explanation:
The work done by the potential difference on the electron is related to the kinetic energy of the electron by this mathematical expression

Making v the subject
Where m is the mass of electron
v is the velocity of electron
q charge on electron
is the potential difference
Substituting values
f

For the electron to move in a circular path the magnetic force[
] must be equal to the centripetal force[
] and this is mathematically represented as

making B the subject

r is the radius with a value = 5.4cm = 
Substituting values


Two objects in physical contact with each other are in thermal equilibrium when they reach the same temperature and an exchange of heat energy no longer occurs.<span> According to HyperPhysics, the relation of thermal equilibrium follows the Zeroth Law of Thermodynamics, which states that “if two systems are at the same time in thermal equilibrium with a third system, they are in thermal equilibrium with each other.” </span>
Answer:
A remote controlled (<em>or externally piloted) </em>sequence valve
Explanation:
First of all, a sequence valve is a pressure-operated valve that opens at an adjustable set pressure.
Sequence valves can be internally piloted or externally piloted.
- Internally piloted sequence valves are known as direct-acting sequence valve. This means that the pressure change they sense is from their main inlet valve.
- Externally piloted sequence valves have a pilot line in which the pilot signal to open the valve is from a source other than the line feeding it.
External pilot-operated sequence valves can be used to open and allow flow when a remote operation reaches a certain predetermined pressure.
Answer:
Explanation:
Given

Motor reverse its direction when \omega =0



(b)




