Answer:
There are three common methods of charging a battery; constant voltage, constant current and a combination of constant voltage/constant current with or without a smart charging circuit.
Constant voltage allows the full current of the charger to flow into the battery until the power supply reaches its pre-set voltage. The current will then taper down to a minimum value once that voltage level is reached. The battery can be left connected to the charger until ready for use and will remain at that “float voltage”, trickle charging to compensate for normal battery self-discharge.
Constant current is a simple form of charging batteries, with the current level set at approximately 10% of the maximum battery rating. Charge times are relatively long with the disadvantage that the battery may overheat if it is over-charged, leading to premature battery replacement. This method is suitable for Ni-MH type of batteries. The battery must be disconnected, or a timer function used once charged.
Constant voltage / constant current (CVCC) is a combination of the above two methods. The charger limits the amount of current to a pre-set level until the battery reaches a pre-set voltage level. The current then reduces as the battery becomes fully charged. The lead acid battery uses the constant current constant voltage (CC/CV) charge method. A regulated current raises the terminal voltage until the upper charge voltage limit is reached, at which point the current drops due to saturation.
Answer:
The source temperature is 1248 R.
Explanation:
Second law efficiency of the engine is the ratio of actual efficiency to the maximum possible efficiency that is reversible efficiency.
Given:
Temperature of the heat sink is 520 R.
Second law efficiency is 60%.
Actual thermal efficiency is 35%.
Calculation:
Step1
Reversible efficiency is calculated as follows:



Step2
Source temperature is calculated as follows:



T = 1248 R.
The heat engine is shown below:
Thus, the source temperature is 1248 R.
Answer:
A tsunami's trough, the low point beneath the wave's crest, often reaches shore first. When it does, it produces a vacuum effect that sucks coastal water seaward and exposes harbor and sea floors. As the tsunami approaches water is drawn back from the beach to effectively help feed the wave. In a tide the wave is so long that this happens slowly, over a few hours.
Explanation:
Answer:
The theoretical density for Niobium is
.
Explanation:
Formula used :

where,
= density of the unit cell
Z = number of atom in unit cell
M = atomic mass
= Avogadro's number
a = edge length of unit cell
We have :
Z = 2 (BCC)
M = 92.91 g/mol ( Niobium)
Atomic radius for niobium = r = 0.143 nm
Edge length of the unit cell = a
r = 0.866 a (BCC unit cell)


On substituting all the given values , we will get the value of 'a'.


The theoretical density for Niobium is
.
Answer:
The answer is "conditionally unstable"
Explanation:
The conditional volatility is really a condition of uncertainty, which reflects on whether increasing air is polluted or not. It determines the rate of ambient delay, which has been between humid and dry adiabatic rates. In general, the environment is in an unilaterally unhealthy region.
Classification dependent on ELR:
Larger than 10
m Around 10 and 6
m or less 6
m volatile implicitly unreliable Therefore ELR is implicitly unreliable 9
m, that's why it is "conditionally unstable".