Answer:
10 V
Explanation:
The potential difference between two points is the amount of work required to carry a unit charge from one point to the other point. This would result in a potential difference between this two points.
The difference between the potential across two points B and A is
From the image attached:
Answer:
The power decreases by 36%
Explanation:
Given:
At 20° C
Power, P₀ = 300 W
Potential difference, V = 150 volts
Now, power is given as
P = V²/R
where, R is the resistance
on substituting the values, we get
300 = 150²/R₀
or
R₀ = 75 Ω
Now, the variation of resistance with temperature is given as
R = R₀[1 + α(T - T₀)]
where, α is the temperature coefficient of resistivity = 0.0003125 (°C⁻¹)
now, at
T₀ = 20° C
R₀ = 75 Ω
for
T = 1820° C
we have
R = R₀[1 + α(T - T₀)]
substituting the values
we get
R = 75×[1 + 0.0003125 × (1820 - 20)]
or
R = 117.18 Ω
Now using the formula for power
We have,
P = V²/R
or
P = 150²/117.18 = 192 W
Therefore, the percentage change will be
=
on substituting the values , we get
=
= -36%
here, negative sign depicts the decrease in power
Answer:
Number of electrons,
Explanation:
A strong lightning bolt transfers an electric charge of about 16 C to Earth, q = 16 C
We need to find the number of electrons that transferred. Let there are n electrons transferred. It is given by using quantization of electric charge as :
q = ne
e is elemental charge
So, there are electrons that gets transferred. Hence, this is the required solution.
Answer:
Explanation:
We know that the frequency of the nth harmonic is given by , where
is the fundamental harmonic. Since we have the values of two consecutive frequencies, we can do:
Which for our values means (we do not need the value of <em>n</em>, that is, which harmonics are the frequencies given):
Now we turn to the formula for the vibration frequency of a string (for the fundamental harmonic):
So the tension is:
Which for our values is: