Answer:
Friction always acts in the direction opposing motion. This means if friction is present, it counteracts and cancels some of the force causing the motion (if the object is being accelerated).
Explanation:
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other.
<u>Answer:</u>
The power and voltage are related through Power Rule
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Explanation :
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Power Rule states that the current I that flows the element in the circuit with a loss in voltage V, then the amount of power dissipated by that element in the circuit is the multiplicative product of voltage and the current.
Mathematically, power law is

The rate of work done or the rate of energy consumption or production is termed as power.Unit of power is denoted as W(watts).
Potential energy between any two points on a circuit is called as Voltage and is measured in volts (V)
.
Explanation:
It is given that,
Magnetic field, B = 0.1 T
Acceleration, 
Charge on electron,
Mass of electron,
(a) The force acting on the electron when it is accelerated is, F = ma
The force acting on the electron when it is in magnetic field, 
Here, 
So, 
Where
v is the velocity of the electron
B is the magnetic field


v = 341250 m/s
or

So, the speed of the electron is 
(b) In 1 ns, the speed of the electron remains the same as the force is perpendicular to the cross product of velocity and the magnetic field.