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24)Revealed: What to expect on Republic Day 2021and what not to

India Republic Day -- Republic Day 2021: In 2020it was the agitation resistant to the Citizenship Amendment Act (CAA). Nowthousands of farmerstypically from Punjab and Haryanahave been camping at the boundaries of Delhi for more than two monthsdemanding the Centre repeal the three farm laws. For the second year in a stripRepublic Day celebrations within the national capital will be kept under the shadow of impetuous protests against laws transferred by the Centre. In 2020it was the agitation resistant to the Citizenship Amendment Act (CAA). This timethousands of farmerstypically from Punjab and Haryanahave been camping at the boundaries of Delhi for more than two monthsdemanding the Centre repeal the three farm laws. This kind of years Republic Day celebration will also be the first major community event in pandemic times. What is new this year The big event will be pared down the number of spectatorsthe size of marching contingents and other side interesting attractions. The specta
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Frequency

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Frequency is the number of occurrences of a repeating event per unit of time. It is also referred to as temporal frequency , which emphasizes the contrast to spatial frequency and angular frequency. Frequency is measured in units of hertz (Hz) which is equal to one occurrence of a repeating event per second. The period is the duration of time of one cycle in a repeating event, so the period is the reciprocal of the frequency. For example: if a newborn baby's heart beats at a frequency of 120 times a minute (2 hertz), its period, T , — the time interval between beats—is half a second (60 seconds divided by 120 beats). Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light.
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Definitions

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For cyclical processes, such as rotation, oscillations, or waves, frequency is defined as a number of cycles per unit time. In physics and engineering disciplines, such as optics, acoustics, and radio, frequency is usually denoted by a Latin letter f or by the Greek letter ν {\displaystyle \nu } or ν (nu) (see e.g. Planck's formula). The relation between the frequency and the period, T {\displaystyle T} , of a repeating event or oscillation is given by f = 1 T . {\displaystyle f={\frac {1}{T}}.}
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Units

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The SI derived unit of frequency is the hertz (Hz), named after the German physicist Heinrich Hertz. One hertz means that an event repeats once per second. If a TV has a refresh rate of 1 hertz the TV screen will change (or refresh) its picture once per second. A previous name for this unit was cycles per second (cps). The SI unit for the period is the second. A traditional unit of measure used with rotating mechanical devices is revolutions per minute, abbreviated r/min or rpm. 60 rpm equals one hertz.
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Period versus frequency

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As a matter of convenience, longer and slower waves, such as ocean surface waves, tend to be described by wave period rather than frequency. Short and fast waves, like audio and radio, are usually described by their frequency instead of period. These commonly used conversions are listed below: Frequency 1 mHz (10−3 Hz) 1 Hz (100 Hz) 1 kHz (103 Hz) 1 MHz (106 Hz) 1 GHz (109 Hz) 1 THz (1012 Hz) Period 1 ks (103 s) 1 s (100 s) 1 ms (10−3 s) 1 µs (10−6 s) 1 ns (10−9 s) 1 ps (10−12 s)
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Related types of frequency

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Angular frequency, usually denoted by the Greek letter ω (omega), is defined as the rate of change of angular displacement, θ , (during rotation), or the rate of change of the phase of a sinusoidal waveform (notably in oscillations and waves), or as the rate of change of the argument to the sine function: y ( t ) = sin ⁡ ( θ ( t ) ) = sin ⁡ ( ω t ) = sin ⁡ ( 2 π f t ) {\displaystyle y(t)=\sin \left(\theta (t)\right)=\sin(\omega t)=\sin(2\mathrm {\pi } ft)} d θ d t = ω = 2 π f {\displaystyle {\frac {\mathrm {d} \theta }{\mathrm {d} t}}=\omega =2\mathrm {\pi } f} Angular frequency is commonly measured in radians per second (rad/s) but, for discrete-time signals, can also be expressed as radians per sampling interval, which is a dimensionless quantity. Angular frequency (in radians) is larger than regular frequency (in Hz) by a factor of 2π. Spatial frequency is analogous to temporal frequency, but the time axis is
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In wave propagation

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For periodic waves in nondispersive media (that is, media in which the wave speed is independent of frequency), frequency has an inverse relationship to the wavelength, λ (lambda). Even in dispersive media, the frequency f of a sinusoidal wave is equal to the phase velocity v of the wave divided by the wavelength λ of the wave: f = v λ . {\displaystyle f={\frac {v}{\lambda }}.} In the special case of electromagnetic waves moving through a vacuum, then v = c , where c is the speed of light in a vacuum, and this expression becomes: f = c λ . {\displaystyle f={\frac {c}{\lambda }}.} When waves from a monochrome source travel from one medium to another, their frequency remains the same—only their wavelength and speed change.
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