1. A student moves a box of books down the hall by pulling on a rope attached to the box. The student

A diode, which allows current to flow in one direction only, consists of two types of semiconductors joined together.

Nata [24]

Answer:

True.

Explanation:

A diode, which allows current to flow in one direction only, consists of two types of semiconductors joined together.

A semiconductor can be defined as a crystalline solid substance that has its conductivity lying between that of a metal and an insulator, due to the effects of temperature or an addition of an impurity. Semiconductors are classified into two main categories;

1. Extrinsic semiconductor.

2. Intrinsic semiconductor.

An intrinsic semiconductor is a crystalline solid substance that is in its purest form and having no impurities added to it. Examples of intrinsic semiconductor are Germanium and Silicon.

In an intrinsic semiconductor, the number of free electrons is equal to the number of holes. Also, in an intrinsic semiconductor the number of holes and free electrons is directly proportional to the temperature; as the temperature increases, the number of holes and free electrons increases and vice-versa.

In an intrinsic semiconductor, each free electrons (valence electrons) produces a covalent bond.

6 0

3 years ago

determine the amount of potential energy of a 5.0-N book that is moved to three different shelves on a bookcase . the height of

klasskru [66]

Potential energy<span> is the </span>energy<span> that is stored in an object due to its position relative to some zero position. It is calculated by the expression PE = mgh where mg is the weight of the book and h is the height. It is calculated as follows:

PE = 50(1) = 50 J
</span>PE = 50(1.5) = 75 J
PE = 50(2) = 100 J

7 0

3 years ago

An L-R-C series circuit, R = 160 Ω , L = 0.790 H , and C = 1.30×10−2 μF . The source has a voltage amplitude of 140 V and a freq

wolverine [178]

Answer: a) 1 b) 61 W c) 61 W

Explanation:

a) The Power Factor (also known as cos φ), is defined by the difference in phase between current and voltage, in a RLC series circuit, and is expressed as follows:

cos φ = R / Z = R / $\sqrt{(R)^{2} + (Xl -Xc)^{2} }$

In resonance, XL =XC, so the circuit behaves like it were purely resistive, so Z=R.

Replacing in the expression for power factor, we have:

cos φ = R/Z = R/R = 1

This means that in resonance, current and voltage are in phase each other.

b) The average power delivered by the source, in resonance, is simply the power dissipated at the resistance R, as follows:

Pavg = V² rms / R = V₀² / √2 / R = 61 W

c) If the circuit remains in resonance, the average power , which does not depends on frequency provided this condition remains, keeps the same, i.e. , 61 W.

7 0

3 years ago

How do we use rock and mineral resources daily?

nikitadnepr [17]

Well minerals are in the water we drink every Day, even the food we eat. Minerals are contained in rocks so there for both are important to life

4 0

3 years ago

Read 2 more answers

A current is established in a gas discharge tube when a sufficiently high potential difference is applied across the two electro

pishuonlain [190]

Explanation:

It is given that the number of electrons passing through the cross-sectional area in 1 s is $3.4 \times 10^{18}$ . Also, we know that charge on an electron is $-1.60 \times 10^{-19} C$ , then negative charge crossing to the left per second is as follows.

I- = $3.4 \times 10^{18} electrons \times -1.6 x 10^{-19} C/electrons$

I- = 0.544 A

As it is given that the number of protons crossing per second is $1.4 \times 10^{18}$ , as the charge on the proton is $+1.60 \times 10^{-19} C$ , then positive charge crossing to the right per second is calculated as follows.

I+ = $1.4 \times 10^{18} electrons \times 1.6 \times 10^{-19} electrons/C$

I+ = 0.224 A

I = l I+ l + l I- l

So, I = 0.544 + 0.224

= 0.768 A

Thus, we can conclude that the current in given hydrogen discharge tube is 0.768 A.

8 0

3 years ago