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3 years ago

7

I have a big test coming up and these two questions i don't understand: Choose the best answer: A device that transforms mechani

cal energy into electrical energy is a/an _______________________. A.conductor B.electric generator C.circuit D.insulator Choose the best answer: The armature in an electric motor spins continuously because ______________________. A.the current can only go in one direction B.the current reverses every half turn C.the current is weak D.the current gets stuck in the armature Thanks :)

1 answer:

Jlenok [28]3 years ago

3 0

1. B- electric generator

Although its really sometimes called an AC generator.

- i hoped i helped u :)

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Rahul kept two plane mirrors at a certain angle in front of a burning candle. He could see 5 images of the candle in the mirrors

Goshia [24]

Answer:

The angle between the mirrors is 90°.

Explanation:

Given that,

Number of image = 5

Rahul kept two plane mirrors at a certain angle in front of a burning candle.

We need to find the angle between the mirrors

Using given data

When Rahul kept two plane mirrors at a certain angle in front of a burning candle then see the 5 image of candle in the mirrors.

If rahul kept two plane mirrors at a 90° then we get the 5 image of candle.

Firstly we see the two images in both mirror and now first image of first mirror is see in second mirror and second image of second mirror is see in first mirror.

So, we can say that we see the 5 image of candle in the mirrors.

Hence, The angle between the mirrors is 90°.

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3 years ago

The maximum amount of static friction between this chair and the floor is 175 N. Which action would cause the chair to move to t

Amiraneli [1.4K]

Answer:

Applying 200 N of force to the chair from the right

Explanation:

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4 years ago

A marathon runner runs at a steady 15 km/hr. When the runner is 7.5 km from the finish, a bird begins flying from the runner to

Whitepunk [10]

Answer:

The value is $D = 15 \ km$

Explanation:

From the question we are told that

The speed of the marathon runner is $v = 15 \ km /hr$

The distance from the distance from the finish is $d = 7.5 \ km$

The speed of the bird is $v_b = 30 \ km / hr$

Generally the time taken for the runner to reach the finish is mathematically represented as

$t = \frac{d}{v}$

$t = \frac{7.5}{15}$

$t = \frac{1}{2}$

So the distance covered by the bird is

$D = v_b * t$

$D = 30 * \frac{1}{2}$

$D = 15 \ km$

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3 years ago

Parallel Plates Consider a very large conducting plate at potential V0 suspended a distance d above a very large grounded plane.

velikii [3]

Answer:

$V = \frac{V_0x}{d}$

Explanation:

Since the field lines are parallel and the electric field is uniform between two parallel plates, a test charge would experience the same force of attraction or repulsion no matter where it is located in the field,

I attached an image that could help to understand the representation of the field. The formula used to calculate it is given by,

$E= -\frac{\Delta V}{x}$ (1)

If we want to consider the change in Voltage with respect to the position then it would be,

$E= -\frac{dV}{dx}$

According to the information provided, the potential is $V_0$ and there is a distance d, therefore

$E= -\frac{V_0}{d}$ (2)

Taking equation (1) we can clear V, to what we have,

$\frac{dV}{dx} = -E$

$dV = -Edx$

Integrating,

$V= - \int Edx$

Substituting (2)

$V = -\int \frac{V_0}{d} dx$

$V = \frac{V_0x}{d}$

Where x is the height from the grounded plate.

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3 years ago

The index of refraction of silicate flint glass for red light is 1.620 and for violet light is 1.660 . A beam of white light in

Alinara [238K]

Answer:

The angular separation between the red and violet components of the spectrum that emerges from the glass is 1.72°

Explanation:

Given:

Refractive index for red light $n _{1} = 1.620$

Refractive index for violet $n' _{1} = 1.660$

Refractive index for air $n_{2} = 1$

Incident angle $\theta _{1} =$ 28.30°

According to the snell's law,

$n_{1} \sin \theta _{1} = n_{2} \sin \theta _{2}$

For red light,

$1.620 \times \sin 28.30 = 1 \sin \theta _{2}$

Where $\theta _{2} =$ transmitted angle for red light

$\theta _{2} =$ 50.18°

For violet light,

$1.660 \times \sin 28.30 = 1 \sin \theta' _{2}$

Where $\theta' _{2} =$ transmitted angle for violet light

$\theta' _{2} =$ 51.9°

Angular separation between red and violet light is given by,

$\theta ' _{2} - \theta _{2} = 51.9 -50.18 =$ 1.72°

Therefore, the angular separation between the red and violet components of the spectrum that emerges from the glass is 1.72°

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3 years ago