Answer:
it is True as the operational definition of electric current.
Explanation:
The definition of electric current is
I = dQ / dt
By convention the direction of the current is the direction in which a positive charge flows.
The initial expression is the derivative that is the change of the load in the unit of time and this occurs in a given cross-sectional cable.
The proposed definition is the same as this, so it is True as the operational definition of electric current.
Answer:
True.
Explanation:
According to Lenz's law, the induced current in a circuit always flows to oppose the external magnetic field through the circuit. This statement is true.
The Faraday's law of induction is given by :

Here, negative sign shows that the direction of induced emf is such that opposes the changing current that is its cause.
Hence, the statement is true.
Answer:
The door will move when the forces exerted by each individual becomes unbalanced.
Explanation:
The Door will only move when the forces exerted by each of the individual is unbalanced i.e. when the Torque is unbalanced
This is because there will only be a reaction or movement of an object when the applied force > resistant force acting on the object.
example : An object at rest will only move when the applied force is greater than the frictional forces acting on the object at rest.
Answer: a) - 437.8° F, b) - 261°c.
Explanation: a) the kelvin and Fahrenheit temperature scale are related by the formulae below.
5 (°F - 32) = 9 (k - 273)
Where °F = temperature in Fahrenheit and k = temperature in kelvin.
For question A, k = 12.0, by substituting to have the value for °F, we have
5(°F - 32) = 9 ( 12 - 273)
5(°F - 32) = 9(-261)
5(°F - 32) = - 2349
°F - 32 = - 2349/5
°F - 32 = - 469.8
°F = - 469.8 + 32
°F = - 437.8
Question B
The centigrade and kelvin scale are related by the formulae below
°c = k - 273
Where °c = temperature in centigrade and k = temperature in kelvin =12
°c = 12 - 273
°c = - 261