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:
Radio waves have a wavelength between 
and 
While,
X rays have a wavelength between 1m and 10km.
=> It is one of the condition of diffraction that the obstacle (coming in the way) must be comparable with the size of the wavelength.
=> This shows, that radio waves have a wavelength which is comparable with the size of buildings and can really easily diffract through it
=> While, X-rays are big enough to diffract through the wall.
So, if an X-ray technician stands behind a wall during the use of her machine, she will remain safe.
Answer:
With the help of formula.
Explanation:
We can calculate the electric potential of any point through the formula of electric potential which is given below.
Electric potential = Coulomb constant x charge/ distance of separation.
Symbolically it can be written as, V = k q/ r where
V = electric potential
k = Coulomb constant
q = charge
r = distance of separation
If we have all these data, we can simply put the data in the formula and we will get the value of electric potential.
Answer:
6.003×10¯⁶ N
Explanation:
We'll begin by converting 1 cm to m. This can be obtained as follow:
100 cm = 1 m
Therefore,
1 cm = 1 cm × 1 m / 100 cm
1 cm = 0.01 m
Finally, we shall determine the gravitational attraction. This can be obtained as follow:
Mass 1 (M₁) = 3 Kg
Mass 2 (M₂) = 3 Kg
Distance apart (r) = 0.01 m
Gravitational constant (G) = 6.67×10¯¹¹ Nm²/Kg²
Force of attraction (F) =?
F = GM₁M₂ / r²
F = 6.67×10¯¹¹ × 3 × / 0.01²
F = 6.003×10¯¹⁰ / 1×10¯⁴
F = 6.003×10¯⁶ N
Thus the gravitational attraction is 6.003×10¯⁶ N
Newton’s second law of motion states that when a force acts on an object, the object’s acceleration is equal to the net force divided by the object’s mass, and is in the same direction as the net force.
