Answer:
Basically, the main risk is cardiac arrest, caused by the electric current interfering with the normal operation of the heart muscle. Other possible damages are burns due to the electric energy vaporizing the water inside the cells, and nerve damage caused by excessive current through the nerves.
The main hazards of working with electricity are:
- Electric shock and burns from contact with live parts.
- Injury from exposure to arcing, fire from faulty electrical equipment or installations.
Explanation:
Pulsar or also sometimes as a actively rotating accretion disc
Answer:b
Explanation:
Given
mass of first cart 
mass of second cart 
velocity of first cart 
conserving momentum



Initial kinetic Energy 


Final Kinetic Energy


Ratio of initial Kinetic Energy to the Final Kinetic Energy

Let current be I, charge be Q and time be t.
Here we are provided with,
I = 0.72A
t = 4s / 60s / 180s / 7s / 0.5s
We know,
I = Q/t
Case I
---------
When, t = 4s
0.72 = Q/4
Q = 0.72 * 4 = 2.88C
Case II
----------
When, t = 60s
0.72 = Q/60
Q = 0.72 * 60 = 43.2C
Case III
-----------
When, t = 180s
0.72 = Q/180
Q = 0.72 * 180 = 129.6C
Case IV
-----------
When, t = 7s
0.72 = Q/7
Q = 0.72 * 7 = 5.04C
Case V
----------
When, t = 0.5s
0.72 = Q/0.5
Q = 0.72 * 0.5 = 0.36C