Daily Science Test 4

In a diode, the anode is the positive terminal and the cathode is the negative terminal. The anode is where the current enters the diode, while the cathode is where the current exits. Therefore, the correct answer is "Anode and Cathode".

When a fast-moving particle collides with a metal, it can cause the ejection of an electron from the metal. This process is known as the photoelectric effect. Therefore, when a fast-moving particle collides with a metal, it is the electron that is emitted.

VLSI stands for Very Large Scale Integration. This term refers to the process of integrating thousands or millions of transistors onto a single chip. VLSI technology has revolutionized the field of electronics by allowing for the creation of smaller, faster, and more complex integrated circuits. With VLSI, it is possible to pack a large number of electronic components onto a small chip, resulting in more efficient and powerful electronic devices.

As the temperature increases, the conductivity of a semi-conductor also increases. This is because at higher temperatures, more electrons are excited from the valence band to the conduction band, creating more charge carriers and increasing the conductivity of the material. Therefore, the statement "বৃদ্ধি পায়" (increases) is the correct answer.

এই প্রশ্নে জিনিসটি যাচাই করার জন্য আমাদেরকে তেজস্ক্রিয়তার বৈশিষ্ট্যগুলি দেখতে হবে। প্রশ্নে দেওয়া বৈশিষ্ট্যগুলির মধ্যে শুধুমাত্র "তেজস্ক্রিয়তা তড়িৎ বা চৌম্বক ক্ষেত্র দ্বারা প্রভাবিত হয়" এই বৈশিষ্ট্যটি তেজস্ক্রিয়তার বৈশিষ্ট্য নয়। তাই এটি সঠিক উত্তর নয়।

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The correct answer is "বাইপোলার" which translates to "bipolar" in English. This answer indicates that BJT (Bipolar Junction Transistor) is a type of transistor that has two types of charge carriers, both electrons and holes, involved in its operation. This distinguishes it from unipolar transistors which only have one type of charge carrier.

এই প্রশ্নে জিজ্ঞাসা করা হয়েছে তেজস্ক্রিয় পদার্থ থেকে আলফা, বিটা ও গামা রশ্মি কেন নির্গত হয়। উত্তরে বলা হয়েছে যে এই রশ্মি স্বতঃস্ফূর্তভাবে নির্গত হয় এর মানে এর জন্য কোন প্রভাব ছাড়া নেই। অর্থাৎ এই রশ্মি নির্গত হতে স্বতঃস্ফূর্তভাবে নির্গমন করে এবং কোন পরবর্তী পদার্থের সাথে সংঘর্ষ বা প্রভাব ছাড়া নিজেই নির্গমন করে।

X-rays are produced by using cathode rays. When high-speed electrons from a cathode strike a metal target, X-rays are generated. Therefore, the correct answer is "ক্যাথোড রশ্মি" (cathode rays).

The correct answer is "উভয় হিসেবেই" (Both as an amplifier and as a switch). Transistors can function as amplifiers by controlling the current or voltage of a signal, allowing it to be amplified. They can also work as switches by either allowing or blocking the flow of current based on the input signal. Therefore, transistors can serve both purposes, making the answer "উভয় হিসেবেই" correct.

Tejascriyata refers to the spontaneous disintegration of the nucleus of an atom. Out of the given options, "পরমাণুর নিউক্লিয়াসের স্বতঃস্ফূর্ত ভাঙ্গন" translates to "spontaneous disintegration of the nucleus of an atom", which aligns with the given definition of tejascriyata. Therefore, this is the correct answer.

The correct answer states that "এর ভেতর দিয়ে রঞ্জন রশ্মি যেতে পারে না" which means that the real diamond cannot emit visible light. This explanation is derived from the given options where it is mentioned that "এর ভিতর দিয়ে রঞ্জন রশ্মি যেতে পারে" which means that visible light can pass through it. Therefore, the correct answer is that the real diamond cannot emit visible light.

When a diode is reverse biased, no current flows through it. The correct information is that "ডায়োড কে রিভার্স বায়াস করলে এর মধ্য দিয়ে তড়িৎ প্রবাহিত হয়" (When a diode is reverse biased, current flows through it). This statement is incorrect because when a diode is reverse biased, the depletion region widens and prevents the flow of current.

Remote sensing refers to the process of collecting information about an object or area from a distance, without physically being present. In this context, the correct answer states that remote sensing involves the observation of the Earth's atmosphere and surface from space using satellites or other spacecraft. This allows for the remote detection and analysis of various features and phenomena on Earth, including the monitoring of weather patterns, land use, and natural resources.

The correct answer is "অর্ধপরিবাহী রেকটিফায়ার" (half-wave rectifier). A p-n junction can act as a rectifier, allowing current to flow in only one direction. In a half-wave rectifier, only half of the AC input waveform is allowed to pass through, resulting in a pulsating DC output.

In the given options, the only component that is not required in the construction of an Integrated Circuit (IC) is an inductor (ইন্ডাক্টর). ICs are made up of transistors, resistors, and capacitors, but not inductors. Inductors are typically used in circuits that involve the generation or manipulation of magnetic fields, which are not typically required in ICs. Therefore, an inductor is not needed in the construction of an IC.

Cobalt-60, a radioactive isotope of cobalt, is used in radiation therapy to destroy tumor cells. It emits high-energy gamma rays that can penetrate tissues and target cancer cells, causing damage to their DNA and preventing them from dividing and growing. This makes cobalt a suitable choice for destroying tumor cells.

The base region of a transistor is the least doped region compared to the emitter and collector regions. The base region is responsible for controlling the flow of current between the emitter and collector regions, and it is the region where the input signal is applied. Therefore, the base region is the least doped region in a transistor.

The correct answer is "ভ্যাকুয়াম টিউব আবিষ্কারের মধ্য দিয়ে" which means "through the invention of the vacuum tube". This suggests that the beginning of electronics was marked by the invention of the vacuum tube. The vacuum tube was one of the earliest electronic devices that allowed the control and amplification of electrical signals. It played a crucial role in the development of early electronic systems and paved the way for subsequent inventions such as transistors and integrated circuits.

The question is asking about the electron that is emitted from the nucleus of a radioactive atom. The correct answer is "বিটা কণা" which refers to the beta particle. Beta particles are high-energy electrons or positrons that are emitted during the radioactive decay of certain atomic nuclei.

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All of the given options (p-n junction, rectifier, diode) are used to convert alternating current (AC) to direct current (DC) and make the flow of current unidirectional. Therefore, all of these options can be used to make the flow of current unidirectional, which is the requirement for changing the direction of the electric current.

Wilhelm Röntgen was the first scientist to receive the Nobel Prize in Physics. In 1901, he was awarded the prize for his discovery of X-rays. Röntgen's discovery revolutionized the field of medicine and had significant implications for various scientific disciplines. His work laid the foundation for the development of medical imaging techniques and greatly contributed to our understanding of the structure of matter. Röntgen's groundbreaking research and its practical applications made him a deserving recipient of the Nobel Prize.

Transistors were first invented and created in the year 1947.

The given options describe the characteristics of X. The first option states that X does not have any charge or mass. The second option states that X has a low refractive index. The third option states that X behaves like a wave. The fourth option states that X is not affected by electric or magnetic fields. Among these options, the correct answer is that X has a low refractive index.

A p-type semiconductor is formed by adding trivalent impurities to a pure semiconductor material. Group III elements in the periodic table are trivalent, meaning they have three valence electrons. Group IV elements have four valence electrons, making them tetravalent. Therefore, when we combine a trivalent element from Group III with a tetravalent element from Group IV, we can create a p-type semiconductor.

A transducer is a device that converts one form of energy into another. In this case, it converts one form of power into another form of power. A transformer, on the other hand, is a device that transfers electrical energy between two or more circuits through electromagnetic induction. A transistor is a semiconductor device that amplifies or switches electronic signals and electrical power. A generator is a device that converts mechanical energy into electrical energy. Therefore, the correct answer is transducer as it best fits the description of converting one form of power into another.

An n-type semiconductor is formed by doping a pure semiconductor with impurities that have more valence electrons than the atoms in the pure semiconductor. Group IV elements, such as silicon and germanium, are commonly used as the base material for semiconductors. Group V elements, such as phosphorus and arsenic, have one extra valence electron compared to the atoms in the pure semiconductor, making them suitable dopants for creating n-type semiconductors. Therefore, when we combine a group IV element with a group V element, we can create an n-type semiconductor.

Madam Curie discovered the existence of three types of active radiation, namely alpha particles, beta particles, and gamma rays. She conducted extensive research on radioactive materials and made significant contributions to the field of nuclear physics. Her discoveries and experiments were instrumental in shaping our understanding of radiation and its properties. Therefore, Madam Curie is the correct answer for proving the existence of three types of active radiation.

The half-life of Uranium-235 is 70 crore years.