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.
A: The positive charge if the protons in the nucleus equals the negative charge in the electron cloud.
Protons are positive, electrons are negative, and neutrons have no charge/are neutral
"Choice-C" is the answer.
Answer:
f = 0.4 Hz
Explanation:
The frequency of rotation of an object in order to achieve required centripetal or radial acceleration, can be found out by using the following formula:
f = (1/2π)√(ac/r)
where,
f = frequency of rotation = ?
ac = radial acceleration = 34.1 m/s²
r = radius = length of beam = 5.55 m
Therefore,
f = (1/2π)√[(34.1 m/s²)/(5.55 m)]
<u>f = 0.4 Hz</u>
