Explanation:
The machine whose efficiency is 100% is known as perfect machine .This machine is not possible in real life because every machine is affected by the overcoming friction due to which is efficiency become less than hundred percent .
Answer:
The thickness of the oil slick is 
Explanation:
Given that,
Index of refraction = 1.28
Wave length = 500 nm
Order m = 1
We need to calculate the thickness of oil slick
Using formula of thickness
Where, n = Index of refraction
t = thickness
= wavelength
Put the value into the formula
Hence, The thickness of the oil slick is
The correct answer of this question is : A) Change alternating current into direct current.
EXPLANATION :
As per the question, we are given vacuum tube. Vacuum tube can be of various types. Normally it contains two electrodes called cathode and anode which are enclosed in an evacuated glass chamber . There are also other types of vacuum tubes which contain extra electrodes like control grid .
The vacuum tube can be used as a rectifier. It means that it can be used as an electronic device which will convert alternating current into direct current. It may be a half wave rectifier or a full wave rectifier. Actually the direct current obtained during the rectification of alternating current is pulsating in nature.
Hence, the correct answer is that a vacuum tube can be used to change alternating current into direct current.
Answer:
D is the answer
Explanation:
6.45×7.44= 47.98800
Which if we round of we get 48m
Answer:
Explanation:
Given
time taken 
Speed acquired in 2 sec 
Here initial velocity is zero 
acceleration is the rate of change of velocity in a given time
Distance travel in this time
where
s=displacement
u=initial velocity
a=acceleration
t=time
so Jet Plane travels a distance of 42 m in 2 s
