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A CE amplifier has a load power of 10mW and the dc power is 215 mW The efficiency is?
Emiliojr
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Why are distribution transformers frequently designed to develop maximum efficiency at loads that are somewhat lower than rated value?
It is always desirable to run any equipment or device at maximum efficiency for that matter, not only the power transformer. Power transformer maximum efficiency occurs when copper loss is equal to iron loss. (or no load loss equals to load loss). This does not necessariliy mean that maximum efficiency occurs at maximum or full load. Generally the maximum efficiency occurs at relatively less than full load of the transformer.
What is the significant relationship of the no load loss in excitation current test in transformer?
The no load losses are the losses caused by energizing the transformer. These are constant losses, regardless of loading. This in effect tells you the efficiency of the transformer. (Power in) - (no load losses) = (Power out)
Can I conect 4 ohm loudspeakers to 8 ohm output of my tube amp as the sound is better?
No. An amplifier designed for an 8 ohm load works best with an 8 ohm load. You can connect a 4 ohm load to it, but the current rating curve of the amplifier will not match the voltage rating curve, and will will not achieve rated power. Attempting to achieve rated power will result in damage to the amplifier. Look at this mathematically... If the amplifier is rated 100 watts into 8 ohms, then it can produce 28 volts doing so. It will also produce 3.5 amperes at that power. So, when we say the amplifier is rated 100 watts into 8 ohms, we mean that the amplifier is rated 28 volts or 3.5 amperes, whichever comes first. Connect a 4 ohm load to this amplifier, and 3.5 amperes will induce 14 volts and 50 watts. You cannot get 100 watts because that would require 5 amperes and 20 volts, and the amplifier cannot produce 5 amperes.
Is your power into motor equal to your power out of motor at no load?
For a motor's output power to equal its input power, the motor's efficiency must be 100%. As no machine, particularly a rotating machine, can possibly achieve 100% efficiency, there is no condition under which its output power can ever match its input power.
What happens when you have a 4 ohm and a 2 ohm sub hooked up to an amplifier?
Yes, you can wire a 6 ohm sub with a 4 ohm sub to the same amplifier, but you need to verify that the amplifier can handle the resulting impedance of 2.4 ohms - many cannot, and could be destroyed. Also, realize that the power in the 4 ohm sub will be greater than the power in the 6 ohm sub.
Why is the output signal affected if the impedance of the amplifier and the load do not match?
A: The signal output will not change it is just that the efficiency of power transfer is effected to less
What is the load resistance of power amplifier?
50
Will the improvement of power factor will increase the efficiency?
Efficiency is defined as the ratio between the output power and the input power of a machine, expressed as a per unit or percentage. Power factor improvement has absolutely no effect on the behaviour of a load. All it does is to reduce the magnitude of the load current. A reduction in load current means that less copper can be used in the supply of energy to the load. However, it doesn't effect either the output or input power of the load. So the answer is no, power factor has no effect on the efficiency of a load. You could argue, however, that if improving the power factor of a load reduces the supply current, leading to lower line losses, then there is an improvement in the efficiency of the supply system.
When a source is delivering maximum power to load the efficiency of the circuit is always?
50%
What is meant by the term large signal amplifier?
power amplifiers are the amplifier which raise the power levels of the signal.the power amplifier may also defined as a device which converts dc power to ac power and whose action is controlled by the ac input signal. Power amplifiers are also known as "LARGE SIGNAL AMPLIFIER".the term large signal arises because they use large part of load line for their operation,but the small signal amplifiers are use only 10% load line for their operation.
What is the efficiency of power transformer at same load at 0.9 lead and 0.9 lag power factor?
Same
Why are distribution transformers frequently designed to develop maximum efficiency at loads that are somewhat lower than rated value?
It is always desirable to run any equipment or device at maximum efficiency for that matter, not only the power transformer. Power transformer maximum efficiency occurs when copper loss is equal to iron loss. (or no load loss equals to load loss). This does not necessariliy mean that maximum efficiency occurs at maximum or full load. Generally the maximum efficiency occurs at relatively less than full load of the transformer.
What voltage is the most effecient when using big equipment?
Generally, voltage has nothing to do with efficiency. Efficiency is the ratio of output power to input power. Higher voltages will, for a given load, result in lower load currents, so less copper is required in to supply that load. So, in that sense, you could say that voltage affects the energy losses in the supply line, which effects efficiency.
Can you use three 8 ohm speakers with one amplifier?
If the amplifier is designed for an 8 ohm load, then you should use an 8 ohm load. Three 8 ohm speaker in series is 24 ohms, and in parallel they are 2.67 ohms. Neither of those is a good match for an 8 ohm rated amplifier. If you do this, you will not achieve rated power, and you may well damage the amplifier.
When is efficiency of 3phased Induction motor maximum what is the condtion for maximum efficiency in induction motor?
It is maximum at about 75% to 100% of the motor rated load. Efficiency is maximum at unity power factor , when R=X and when variable losses Is equal to constant losses at rated load.
What is transformer coupling in power amplifiers?
in certain power amplifiers(cls A,cls C etc.) the output sometimes not directly taken. rather it's coupled with transformer and then transferred power is applied to the load..this is transformer coupling..... there are two main reasons to do so 1. in order to increase the efficiency.(exmpl: efficiency of class A power amplifier increase by almost 25%) 2.in order to get smooth i.e; distortion less output.. by Jishnu Mukherjee (Kolkata,India)
Will a power setting for 8 ohm speaker damage a 6 ohm speaker?
Maybe. And it might also damage the amplifier. It depends on what power level you try to use. An amplifier designed for an 8 ohm speaker will push a certain current into that 8 ohms and be able to generate a certain voltage and power. All amplifiers have limits on both current and voltage, and they are optimized for a certain impedance load so that those limits occur at approximately the same point in power production. If you replace the intended 8 ohm load with a 6 ohm load, then the same voltage will generate more current and more power. Similarly, the same current will generate less voltage and less power. So, the answer is that, unless you match the amplifier's intended load impedance, you will not achieve rated power, because either the amplifier's voltage limit or its current limit will be reached earlier than expected. If you try to achieve rated power with a mismatched load, something is going to break, most probably the speaker, but the amplifier is also at risk.
