Answer: conductors are substances that allow heat or electricity to pass through . It deals with only the flow of electrons.
Eg. water, copper wire, iron rod, some ceramic materials, metallic nail.
Insulators are materials that do not allow heat or electricity to pass through.
Eg. Book, plastic, rubber, glass, paper
Explanation:
Answer:

Explanation:
In this case, since the charged particle moves in circular motion, the centripetal force is equivalent to the magnetic force.

Answer:
Yes
Explanation:
Given that the battery is the same the PD ( potential difference ) in the circuit will also be the same likewise the flow of charge in the circuit,
Hence the same amount of charge flow is delivered to any circuit.
attached below are examples
Answer: There is not work done at the door because the door did not move.
Explanation: Work is defined as the movement done by a force.
So if you move to apply a force F in an object and you move it a distance D, the work applied on the object is
W = F*D
In this case, the secret agent pushes against the door, so there is a force, but the agent does not move the door, so D = 0, so there is no motion of the door, which implies that there is no work done at the door.
There are two external force acts on the chair.
1. The force due to earth gravity, acts in the downward direction.
2. Reaction force of the gravity, which acts in the Upward direction (Normal Force).
On every object, there is a force acts due to gravity of earth, which pulls the object towards the centre of earth, known as gravity force, always acts in the downward direction. Mathematically it's given as
F=mg
here, m is the mass of the object, and g is the acceleration of gravity.
To balance this gravity force, a counter force acts in the opposite direction, whose magnitude is equal to the force of gravity