Answer: Option A
Explanation:
The potential energy decreases in the case when the charges are opposite and they attract each other.
In this case there is no external energy required in order to put the charges together.
This is so because the charges are opposite and they will attract each other. Yes, the only condition should be that the charges should be alike.
Example: a negative charge and a positive charge.
a) Work done = Net Kinetic Energy
= 1/2 x 50 kg x ((12m/s)^2 - (3m/s)^2)
= 0.5 x 50 Kg x (144 -9)(m/s)^2
= 3375 Kg (m/s)^2
b) Force = mxa
a = 120 N/50 Kg = 2.4 m/s^2
Using newtons third law of motion, we get-
V^2 - U^2 = 2 x a x S
S= (12^2-3^2)m^2/s^2/(2 x 2.4 m/s^2)
= 28.125 m
Answer:
A: They produce a real image.
Explanation:
The images formed on the retina of the eye for a normal visibility must always be real.
Only a real image can be physically projected on any physical object whereas the virtual images are visible due to reflections.
- The nearsightedness is corrected with the help of a concave lens since it is the condition of the eye lens remaining thick and curved to converge the rays entering the eyes after a shorter distance which results in their image formation even before the retinal surface so to initially diverge them a bit so that they converge on the retinal surface and form the image there we use concave lens. Vice-versa of the above justification in the case of farsightedness.
The devices don't "draw" 120v. The 120v comes to your house from the power company. They decide it should be 120v and that's what they send you. It's hypothetically technically possible for you to change that, but if you try it, you'll definitely burn the house down.
The total resistance of those two devices in parallel is 6 and 2/3 ohms. That doesn't depend on what they're plugged into. It would still be 6 and 2/3 ohms if they were connected in parallel, wrapped in tissue, sealed in a jar of chicken soup and stored in a box on a high shelf.
But since they ARE plugged into 120v, they draw 18 Amperes from the socket, and they turn all of that electrical energy into 2160 watts of heat. That's about the same as a good size toaster oven, and you have to figure out a way to get rid of all that heat before you burn the house down.
Answer:
B: Relay
Explanation:
Out of all the options, the only device that relies upon the magnetic field of an electric current.
The principle relies upon the principle of electro magnetic attraction whereby when the circuit detects a faulty current, it makes the electromagnetic field to become energized which in turn produces the temporary magnetic field. This magnetic field then moves the relay armature which is used in opening or closing the connections.
