Answer: Only Tech B is correct.
Explanation:
First, tech A is wrong.
The circuits that can be compared with links in a chain are the series circuit, and it can be related to the links in a chain because if one of the elements breaks, the current can not flow furthermore (because the elements in the circuit are connected in series) while in a parallel circuit if one of the branches breaks, the current still can flow by other branches.
Also in a parallel circuit, the sum of the currents of each path is equal to the current that comes from the source, so Tech B is correct, the total current is equal to the sum of the currents flowing in each branch of the circuit.
Answer:
A. 
B. t = 50 s
Explanation:
A. The vectorial equation of the person who is getting closer to the other person is:
r: position vector
v: speed vector = 6m/s i (if you consider the motion as a horizontal motion)
Then, you replace and obtain:
B. The time is:
d: distance to the observer = 300m
v: speed of the person on the car = 6.00 m/s
A decrease in it's operating temperature would make a heat engine less efficient. This is because in order to operate, a heat engine needs to be hot and maintain that temperature.
Answer: Option (A) and (D) are the correct statements.
Explanation:
Potential energy is defined as the energy obtained by an object due to its position. Whereas kinetic energy is defined as the energy obtained by an object due to the motion of its molecules.
When there will be only one phase present then addition or removal of energy will lead to change in kinetic energy of the substance but no change in potential energy will take place.
Whereas if change in phase is occurring then adding or removing any energy will lead to change in potential energy of the substance while kinetic energy will remain the same.
Thus, we can conclude that correct statements are as follows.
- While only one phase is present, adding or removing energy changes PE but not KE.
- During a phase change, adding or removing energy changes PE but not KE.
