Answer:
The tube should be held vertically and perpendicular to the ground.
Explanation:
Answer: The tube should be held vertically and perpendicular to the ground. The reason is as follows:
Reasoning:
The power lines are parallel to the ground hence, their electric field will be perpendicular to the ground and equipotential surface will be cylindrical.
Hence, if you will put fluorescent tube parallel to the ground then both the ends of the tube will lie on the same equipotential surface and the potential difference will be zero.
So, to maximize the potential the ends of the tube must be on different equipotential surfaces. The surface which is near to the power line has high potential value and the surface which is farther from the line has lower potential value.
hence, to maximize the potential difference, the tube must be placed perpendicular to the ground.
To solve this problem we will use the linear motion description kinematic equations. We will proceed to analyze the general case by which the analysis is taken for the second car and the tenth. So we have to:

Where,
x= Displacement
= Initial velocity
a = Acceleration
t = time
Since there is no initial velocity, the same equation can be transformed in terms of length and time as:

For the second cart

When the tenth car is aligned the length will be 9 times the initial therefore:

When the tenth car has passed the length will be 10 times the initial therefore:

The difference in time taken from the second car to pass it is 5 seconds, therefore:

From the first equation replacing it in the second one we will have that the relationship of the two times is equivalent to:


From the relationship when the car has passed and the time difference we will have to:



Replacing the value found in the equation given for the second car equation we have to:

Finally we will have the time when the cars are aligned is


The time when you have passed it would be:


The difference between the two times would be:

Therefore the correct answer is C.
Formula for potassium dichromate is
K2Cr2O7
Answer:
Explanation:
The calcite Crystal can be identified by carrying out an acid test on it. This is done by bringing it in contact with a weak acid which cause crack in it structure. Hence a little of carbondioxide gas is released.
Since diamond is the hardest object,it can be identified on a Mohs scale. Likewise it can be tested by bringing it in contact with a newspaper, if the letters on the paper are not seen, that shows it is a pure diamond.
Window glass is identified by the code on it.
While Quartz Crystal is identified by scratch test. When it is used to scratch all other softer stones and metal, it leaves mark on them.