1) The charge left on the fur is equal and opposite to the charge transferred to the rod:
In fact, when the rod is rubbed with the fur, a net charge of
has been transferred to the rod, leaving it negatively charged. If we assume the fur was initially neutral, this means that we have now an excess of positive charges on the fur, and the amount of this charge must be equal (in magnitude, but with opposite sign) to the charge transferred to the rod.
2) The mass transferred to the rod is equal to the total mass of the electrons transferred to the rod.
The charge transferred to the rod is
The charge of 1 electron is
So the number of electrons transferred is
The mass of 1 electron is
, therefore the total mass transferred to the rod is
The first part of the microscope that should first be used to adjust the focus when starting with the lowest power lens would be the coarse adjustment knob.
There are two knobs in a typical light microscope with which objects on slides can be brought into focus:
- Coarse adjustment knob
- Fine adjustment knob
The 2 knobs are used to adjust the stage to either bring it up towards the objective lens or down away from them. The coarse adjustment knob, however, moves the stage a considerable distance with each turn. The fine adjustment knob, on the other hand, only moves the stage very little with each turn.
The lowest power lenses are often short. Hence, using the coarse adjustment knob is ideal in order to quickly bring objects on slides into focus.
The fine adjustment knob comes highly recommended at high objectives because high objectives lenses are usually long and using the coarse adjustment knob can lead to a breakage of the slide by the lens.
More on bringing objects into focus on a microscope can be found here: brainly.com/question/24319677
An example is free fall ,
<h3><u>Given :- </u></h3>
- Length of the rectangular wire, L=0.3 m
- Width of the rectangular wire, b=0.2m
- Magnetic field strength, B=0.8 T
- Velocity of the loop, v =12 m/s
- Induced Current, I = 3 A
(I) Emf developed,E in the loop is given as:
I = E/R
R = E/I
where
- R = resistance
- E = Induced EMF
- I = Current
(ii) The direction of current induced is from P to Q which is given by B × V vector . It may also be explained by Lenz law. Since magnetic field is from S to N . The fingers of the right hand are placed around the wire so that the curling of fingers will show the direction of the magnetic field produced by the wire then the thumb points in the direction of current flow which is from P to Q.
