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3 years ago

14

The potential difference across a resistor in a particular electric circuit is 420 V. The current through the resistor is 19.0 A

. What is its resistance (in Ω)?

1 answer:

damaskus [11]3 years ago

7 0

Answer: 22.11 ohms

Explanation:

Potential difference(v)=420V

Current(I)=19.0 amp

Resistance(r)=?

r=v/I

r=420/19.0

r=22.11 ohms

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Water flows in a 0.15-m-diameter vertical pipe at a rate of 0.20 m3/s and a pressure of 210 kPa at an elevation of 25 m. Determi

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Answer:

(a). The velocity head at elevation of 20 m is 6.52 m/s.

(b). The pressure head at elevation of 20 m is 26.42 m.

(c). The velocity is 6.52 m/s.

(d). The pressure head at elevation of 55 m is 16.42 m.

Explanation:

Given that,

Vertical diameter = 0.15 m

Rate =0.20 m³/s

Pressure = 210 kPa

Elevation = 25 m

We need to calculate the velocity

Using formula of velocity

$Q=vA$

$v=\dfrac{Q}{A}$

Put the value into the formula

$v=\dfrac{0.20}{\pi\dfrac{D^2}{4}}$

$v=\dfrac{0.20}{\pi\dfrac{0.15^2}{4}}$

$v=11.31\ m/s$

Since, Q is constant, A is constant so v will be constant everywhere.

(a). We need to calculate the velocity head at elevation of 20 m

Using formula of velocity head

$v'=\dfrac{v^2}{2g}$

Put the value into the formula

$v'=\dfrac{11.31^2}{2\times9.8}$

$v'=6.52\ m/s$

The velocity head at elevation of 20 m is 6.52 m/s.

(b). We need to calculate pressure head at elevation of 20 m,

Using Bernoulli equation

$h+\dfrac{p}{\rho g}+\dfrac{v^2}{2g}=constant$

$h+\dfrac{p}{\rho g}=constant$

Here, velocity is constant

At h = 20 m

$20+P_{H}=25+\dfrac{210\times10^{3}}{1000\times9.8}$

$P_{H=46.42-20$

$P_{H}=26.42\ m$

The pressure head at elevation of 20 m is 26.42 m.

(c). We need to calculate the velocity head at elevation of 55 m,

The velocity is v'=6.52 m/s.

(d). We need to calculate the pressure head at elevation of 55 m

Using formula again

At h = 55 m

$h=55+P_{H}$

$55+P_{H}=25+46.42$

$P_{H}=25-55+46.42\ m$

$P_{H}=16.42\ m$

The pressure head at elevation of 55 m is 16.42 m.

Hence, this is the required solution.

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Answer:

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h = Height of lift = 1.47 m

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g = Acceleration due to gravity = 9.81 m/s²

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$W=mgh\\\Rightarrow W=102\times 9.81\times 1.47\\\Rightarrow W=1470.9114\ J$

For 10 times

$W=10\times 1470.9114\\\Rightarrow W=14709.114\ J$

Power is given by

$P=\dfrac{W}{t}\\\Rightarrow P=\dfrac{14709.114}{14}\\\Rightarrow P=1050.651\ W$

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$y_n = \frac{(2n-1)\lambda D}{2d}$

$D = \frac{2dy_n}{(2n-1)\lambda}$

Here,

d = Slit separation

n = Number of fringe

$y_n$ = Distance of the dark fringe from the central maximum

D = Distance of the screen to the slit

$\lambda$ = Wavelength

Our values are given as,

$\lambda = 679nm = 679*10^{-9}m$

$d = 1.1mm = 1.1*10^{-3}m$

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Replacing,

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