B. Write true or false for the following statements.

☆ Correct and rewrite the following statements:

il63 [147K]

Answer:

<h3>a) </h3><h3>Question:-</h3>

Rubber is a good conductor of electricity.

<h3>Answer:-</h3>

It's incorrect sentence.
As we know that, rubber are an insulators of electricity, and they do not not have free ions which can help in conducting electricity.

So correct sentence is:

Rubber is a bad conductor of electricity.

<h3>b)</h3><h3>Question:-</h3>

Electroplating wastes are useful to human health and environment.

<h3>Answer:-</h3>

It's incorrect sentence. 
As we know that, electroplating of substances releases harmful and toxic substances into the environment causing serious health issues in human, so it's waste substances released into environment can have very harmful effects.

So correct sentence is:

Electroplating wastes are harmful to human health and environment.

<h3>c)</h3><h3>Question:-</h3>

In an LED bulb, the shorter lead is connected to the positive terminal of the battery.

<h3>Answer:-</h3>

It's incorrect sentence. 
As we know that, in an LED bulb their are two terminals that is the positive and the negative. So here the lead connected to the positive terminal is always slightly longer than the lead connected to negative terminal of the bulb.

So correct sentence is:

In an LED bulb, the longer lead is connected to the positive terminal of the battery.

<h3>d)</h3><h3>Question:-</h3>

Pure water conducts electricity.

<h3>Answer:-</h3>

It's incorrect sentence. 
As we know that, pure water is a form of H2O where Hydrogen (H) is positive ion and Oxygen (O) is a negative ion which can conduct electricity when they are in individuals but as in pure water they are in combined form of compound H2O in which they become neutral and can't conduct any electricity.

So correct sentence is:

Pure water can't conduct electricity.

3 0

2 years ago

Three perfectly polarizing sheets are spaced 2?cm {\rm cm} apart and in parallel planes. The transmission axis of the second she

Agata [3.3K]

Answer:

I₃/Io % = 0.8.59

Explanation:

A polarizer is a complaint sheet for light in the polarization direction and blocks the perpendicular one. When we use two polarizers the transmission between them is described by Malus's law

I = I₀ cos² θ

Let's apply the previous exposures in our case, the light is indicatively not polarized, so the first polarized lets half of the light pass

I₁ = ½ I₀

The light transmitted by the second polarizer

I₂ = I₁ cos² θ

I₂ = (½ I₀) cos2 28

The transmission by the polarizing third is

I₃ = I₂ cos² θ₃

The angle of the third polarizer with respect to the second is

θ₃ = 90-28

θ₃ = 62º

I₃ = (½ I₀ cos² 28 cos² 62)

Let's calculate

I₃ = Io ½ 0.7796 0.2204

I₃ = Io 0.0859

I₃/Io= 0.0859 100

I₃/Io % = 0.8.59

4 0

4 years ago

Cousin Throckmorton is playing with the clothesline. One end of the clothesline is attached to a vertical post. Throcky holds th

Oksi-84 [34.3K]

Answer:

The frequencies are $f_n = n (0.875 )$

Explanation:

From the question we are told that

The speed of the wave is $v = 0.700 \ m/s$

The length of vibrating clothesline is $L = 40.0 \ cm = 0.4 \ m$

Generally the fundamental frequency is mathematically represented as

$f = \frac{v}{2 L }$

=> $f = \frac{ 0.700 }{2 * 0.4 }$

=> $f = 0.875 \ Hz$

Now this other frequencies of vibration experience by the clotheslines are know as harmonics and they are obtained by integer multiple of the fundamental frequency

So

The frequencies are mathematically represented as

$f_n = n * f$

=> $f_n = n (0.875 )$

Where n = 1, 2, 3 ....

3 0

3 years ago

Impact of electricity in the society

Travka [436]

Answer:

<h2>Electricity has many uses in our day to day life. It is used for lighting rooms, working fans and domestic appliances like using electric stoves, A/C and more. All these provide comfort to people. In factories, large machines are worked with the help of electricity.</h2>

5 0

2 years ago

We have seen that an electric field must exist inside a conductor that carries a current. How is that possible in view of the fa

sleet_krkn [62]

Answer:

Explanation:

The potential difference between one side of the wire causes the electric field inside the wire (causes the electrons to flow). However, inside the wire, it is still neutral. The electrons are just moving, the wire is not gaining or losing electrons.

7 0

3 years ago