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3 years ago

Electricity cost 10p how much will it cost to use a 85w laptop and a 60w lamp for an hour

Physics

1 answer:

Reil [10]3 years ago

7 0

Answer:

Explanation:

usually electricity is sold in the units of kWh, which I will ASSUME is the case here.

85 W (1 kW/1000W)(1hr)(10 p) = 0.85p

60 W (1 kW/1000W)(1hr)(10 p) = <u>0.60p</u>

together they would cost 1.45 p

which would be rounded down to 1 p

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Which branch of science includes the laws of matter and energy?

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3 years ago

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Why did thomson’s results from experimenting with cathode rays cause a big change in scientific thought about atoms?

natima [27]

Answer:

Explanation:

Before Thomson's discovery, atoms were believed according to the "Dalton's atomic theory" to be the smallest indivisible particle of any matter. This makes atoms the smallest unit of a matter.

Thomson in 1897, used the discharge tube to discover cathode rays which are today called electrons.

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3 years ago

Two solenoids A and B, spaced close to each other and sharing the same cylindrical axis, have 430 and 610 turns, respectively. A

KIM [24]

Answer

given,

Two solenoids A and B

Number of turn

Na = 430 turns Nb = 610 turns

Current = 2.80 A

Average flux through A = 300 μWb

Average of flux through B = 90.0 μ Wb

a) $L = \dfrac{N \phi}{I}$

$L = \dfrac{610\times 90 \times 10^{-6}}{2.80}$

$L =19.6 mH$

b) inductance of A

$L = \dfrac{N_A \phi_A}{I_A}$

$L = \dfrac{430\times 300 \times 10^{-6}}{2.80}$

$L =46 mH$

c) magnitude of the emf

$\epsilon_B = -L_B\dfrac{dI}{dT}$

$\epsilon_B = -(19.6\times 10^{-3})(0.5)$

$\epsilon_B = -9.8\times 10^{-3}\ V$

$\epsilon_B = -9.8\ mV$

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3 years ago

In an RLC series circuit that includes a source of alternating current operating at fixed frequency and voltage, the resistance

maw [93]

Answer:

Capacitive Reactance is 4 times of resistance

Solution:

As per the question:

R = $X_{L} = j\omega L = 2\pi fL$

where

R = resistance

$X_{L} = Inductive Reactance$

f = fixed frequency

Now,

For a parallel plate capacitor, capacitance, C:

$C = \frac{\epsilon_{o}A}{x}$

where

x = separation between the parallel plates

Thus

C ∝ $\frac{1}{x}$

Now, if the distance reduces to one-third:

Capacitance becomes 3 times of the initial capacitace, i.e., x' = 3x, then C' = 3C and hence Current, I becomes 3I.

Also,

$Z = \sqrt{R^{2} + (X_{L} - X_{C})^{2}}$

Also,

Z ∝ I

Therefore,

$\frac{Z}{I} = \frac{Z'}{I'}$

$\frac{\sqrt{R^{2} + (R - X_{C})^{2}}}{3I} = \frac{\sqrt{R^{2} + (R - \frac{X_{C}}{3})^{2}}}{I}$

${R^{2} + (R - X_{C})^{2}} = 9({R^{2} + (R - \frac{X_{C}}{3})^{2}})$

${R^{2} + R^{2} + X_{C}^{2} - 2RX_{C} = 9({R^{2} + R^{2} + \frac{X_{C}^{2}}{9} - 2RX_{C})$

Solving the above eqn:

$X_{C} = 4R$

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3 years ago

Electrons and protons travel from the Sun to the Earth at a typical velocity of 3.83 ✕ 105 m/s in the positive x-direction. Thou

Leona [35]

Answer:

$F=2.84*10^{-26}N$ & -y direction

$F=2.84*10^{-26}N$ & +y direction

Explanation:

From the question we are told that:

Speed of electron $V_e=3.83 * 10^5 m/s$ +x direction

Earths magnetic field $B_e=3.04 * 10^-^8$ +z direction

Generally the equation for magnetic force $F_m$ is mathematically given by

$F=q(V_e*B_e)$

where

$q=1.6*10^{-19}c\\\=i*\=z=-\=j$

$F=1.6*10^{-19}(3.83 * 10^5 m/s*3.04 * 10^-^8)$

$F=-2.84*10^{-26}N \=j$

Magnitude & Direction

$F=2.84*10^{-26}N$ -y direction

Generally the equation for magnitude and direction of the magnetic force on an electron. is mathematically given by

$\=F'=-1.6*10^{-19}(3.83 * 10^5 m/s*3.04 * 10^-^8)$

$\=F'=-2.84*10^{-26}N \=j$

Magnitude & Direction

$F=2.84*10^{-26}N$ & +y direction

5 0

3 years ago