Resistors and reactors, for use over 600 volts, shall not be installed in close enough proximity to combustible materials to constitute a fire hazard and shall have a clearance of not less than<u> 300 mm </u>from combustible materials.
Explanation:
- The hazards associated with high power industrial resistors are primarily due to their open construction, which is necessary for cooling.
- The exposed conductors which make up the resistors can be not only a shock hazard but also a thermal burn hazard.
- When a resistor fails, it either goes open or the resistance increases. When the resistance increases, it can burn the board, or burn itself up.
- Avoid touching non-flammable resistors in operation; the surface temperature ranges from approximately 350 °C to 400°C when utilized at the full rated value. Maintaining a surface temperature of 200°C or less will extend resistors service life.
- Do not apply power to a circuit while measuring resistance. When you are finished using an ohmmeter, switch it to the OFF position if one is provided and remove the leads from the meter.
- Always adjust the ohmmeter for 0 (or in shunt ohmmeter) after you change ranges before making the resistance measurement.
The atom that would least likely form chemical bonds with other atoms would be C. A neon containing 4 valence electrons, this is because neon itself is an inert gas, it would not necessarily react as it already possess the maximum number of electrons needed to achieve stability and have a full octet, even if it is forced to obtain 4 valence electrons it would not react with other atoms.
Answer:
Explanation:
Given
Sphere of Radius R
Suppose mass of block is m
At any instant \theta Normal reaction(N) and weight(mg) is acting such that
, where v is velocity of block at any angle \theta
When block is just about to leave then N=0
therefore
-------------------1
Also by conserving Energy we get
Potential Energy=kinetic Energy of block
here h=vertical distance traveled by block
From diagram
-----------------2
From 1 and 2
Thus from this value of h is
Answer:
critical angle is the angle of incidence in optically denser medium, for which the angle of reflection in the less denser medium is 90 degree
Explanation:
total internal reflection occurs at one particular angle of incidence where the reflected ray lies on the boundary.
this angle is called the critical angle
