ANSWER is c
HOPR THIS WILL BE HELPFUL
Machines are never 100% efficient because they are made by humans and we make errors and nothing we make is perfect, that's why the machines we build are not 100% accurate or efficient.
Answer: D
Key thing to keep note, is "refraction"...
Look at some experiments on YouTube, it's helps me a lot.
Explanation:
Average speed = distance / time
|v| = (7 km + 2 km) / (2 hr + 1 hr)
|v| = 3 km/hr
Average velocity = displacement / time
v = (7 km east + 2 km east) / (2 hr + 1 hr)
v = 3 km/hr east
Answer:
The maximum no. of electrons- 
Solution:
As per the question:
Maximum rate of transfer of charge, I = 1.0 C/s
Time, t = 1.0 h = 3600 s
Rate of transfer of charge is current, I
Also,

Q = ne
where
n = no. of electrons
Q = charge in coulomb
I = current
Thus
Q = It
Thus the charge flow in 1. 0 h:

Maximum number of electrons, n is given by:

where
e = charge on an electron = 
Thus
