Answer:Transformer
Explanation:All the other devices generate their own electricity apart from power line and Transformer, power line just carries electricity. A transformer can be used to step up or step down voltages from a source.
<span>(c) energy travels from the object at higher temperature
to the object at lower temperature.
Size and mass have no effect.</span>
Answer : The correct option is, (D) 278 K
Explanation :
We are given temperature .
Now the conversion factor used for the temperature is,
where, K is kelvin and is Celsius.
Now put the value of temperature, we get
Therefore, the temperature 278 K is equal to the
Answer:
It would take time for the capacitor to discharge from to .
It would take time for the capacitor to discharge from to .
Note that , and that.
Explanation:
In an RC circuit, a capacitor is connected directly to a resistor. Let the time constant of this circuit is , and the initial charge of the capacitor be . Then at time , the charge stored in the capacitor would be:
.
<h3>a)</h3>
.
Apply the equation :
.
The goal is to solve for in terms of . Rearrange the equation:
.
Take the natural logarithm of both sides:
.
.
.
<h3>b)</h3>
.
Apply the equation :
.
The goal is to solve for in terms of . Rearrange the equation:
.
Take the natural logarithm of both sides:
.
.
.
Answer:
C) Use two batteries instead of one.
Explanation:
-Strength of an electromagnet depends on the electrical current which flows through the wires.
-Two batteries have a higher current than one and thus higher strength in the electromagnet.