Physics miscellaneous
- When a vibrating tuning fork is placed on a table, a loud sound is heard. This is due to :
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The tendency of one object to force another adjoining or interconnected object into vibrational motion is referred to as a forced vibration. In the case of the guitar string mounted to the sound box, the fact that the surface area of the sound box is greater than the surface area of the string means that more surrounding air particles will be forced into vibration. This causes an increase in the amplitude and thus loudness of the sound. This same principle of a forced vibration is often demonstrated in a Physics classroom using a tuning fork. If the tuning fork is held in hand and hit with a rubber mallet, a sound is produced as the tines of the tuning fork set surrounding air particles into vibrational motion. The sound produced by the tuning fork is barely audible to students in the back rows of the room. However, if the tuning fork is set upon the whiteboard panel or the glass panel of the overhead projector, the panel begins vibrating at the same natural frequency of the tuning fork.
Correct Option: C
The tendency of one object to force another adjoining or interconnected object into vibrational motion is referred to as a forced vibration. In the case of the guitar string mounted to the sound box, the fact that the surface area of the sound box is greater than the surface area of the string means that more surrounding air particles will be forced into vibration. This causes an increase in the amplitude and thus loudness of the sound. This same principle of a forced vibration is often demonstrated in a Physics classroom using a tuning fork. If the tuning fork is held in hand and hit with a rubber mallet, a sound is produced as the tines of the tuning fork set surrounding air particles into vibrational motion. The sound produced by the tuning fork is barely audible to students in the back rows of the room. However, if the tuning fork is set upon the whiteboard panel or the glass panel of the overhead projector, the panel begins vibrating at the same natural frequency of the tuning fork.
- The filament of electric bulb is made up of :
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An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light which produces light with a filament wire heated to a high temperature by an electric current passing through it, until it glows. Tungsten, also known as wolfram, is a chemical element. Tungsten’s many alloys have numerous applications, most notably in incandescent light bulb filaments, X-ray tubes (as both the filament and target), electrodes in TIG welding, and superalloys.
Correct Option: D
An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light which produces light with a filament wire heated to a high temperature by an electric current passing through it, until it glows. Tungsten, also known as wolfram, is a chemical element. Tungsten’s many alloys have numerous applications, most notably in incandescent light bulb filaments, X-ray tubes (as both the filament and target), electrodes in TIG welding, and superalloys.
- In the absence of ozone layer, which rays will enter into atmosphere?
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The ozone layer is a layer in Earth’s atmosphere containing relatively high concentrations of ozone (O3). The ozone layer absorbs 97–99% of the Sun’s mediumfrequency ultraviolet light (from about 200 nm to 315 nm wavelength), which potentially damages exposed life forms on Earth. Although the concentration of the ozone in the ozone layer is very small, it is vitally important to life because it absorbs biologically harmful ultraviolet (UV) radiation coming from the sun. Extremely short or vacuum UV (10-100 nm) is screened out by nitrogen.
Correct Option: C
The ozone layer is a layer in Earth’s atmosphere containing relatively high concentrations of ozone (O3). The ozone layer absorbs 97–99% of the Sun’s mediumfrequency ultraviolet light (from about 200 nm to 315 nm wavelength), which potentially damages exposed life forms on Earth. Although the concentration of the ozone in the ozone layer is very small, it is vitally important to life because it absorbs biologically harmful ultraviolet (UV) radiation coming from the sun. Extremely short or vacuum UV (10-100 nm) is screened out by nitrogen.
- In the absence of ozone layer, which rays will enter into atmosphere?
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The ozone layer is a layer in Earth’s atmosphere containing relatively high concentrations of ozone (O3). The ozone layer absorbs 97–99% of the Sun’s mediumfrequency ultraviolet light (from about 200 nm to 315 nm wavelength), which potentially damages exposed life forms on Earth. Although the concentration of the ozone in the ozone layer is very small, it is vitally important to life because it absorbs biologically harmful ultraviolet (UV) radiation coming from the sun. Extremely short or vacuum UV (10-100 nm) is screened out by nitrogen.
Correct Option: C
The ozone layer is a layer in Earth’s atmosphere containing relatively high concentrations of ozone (O3). The ozone layer absorbs 97–99% of the Sun’s mediumfrequency ultraviolet light (from about 200 nm to 315 nm wavelength), which potentially damages exposed life forms on Earth. Although the concentration of the ozone in the ozone layer is very small, it is vitally important to life because it absorbs biologically harmful ultraviolet (UV) radiation coming from the sun. Extremely short or vacuum UV (10-100 nm) is screened out by nitrogen.
- Gamma rays have greatest similarity with
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Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as y, is electromagnetic radiation of high frequency and therefore high energy. Gamma rays are ionizing radiation and are thus biologically hazardous. They are classically produced by the decay from high energy states of atomic nuclei (gamma decay), but are also created by other processes. X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays
have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3×1016 Hz to 3×1019 Hz) and energies in the range 100 eV to 100 keV. They are shorter in wavelength than UV rays and longer than gamma rays.Correct Option: C
Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as y, is electromagnetic radiation of high frequency and therefore high energy. Gamma rays are ionizing radiation and are thus biologically hazardous. They are classically produced by the decay from high energy states of atomic nuclei (gamma decay), but are also created by other processes. X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays
have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3×1016 Hz to 3×1019 Hz) and energies in the range 100 eV to 100 keV. They are shorter in wavelength than UV rays and longer than gamma rays.