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अब औरत को लुगाई पढेंगे बच्चे

अब नई शिक्षा नीति के तहत मातृ भाषा में होगी प्राथमिक स्तर तक की पढ़ाई, औरत को लुगाई पढेंगे बच्चे शेखावटी के प्राथमिक स्कूलों के विद्यार्थी अब औरत को लुगाई, आग को बासते और इंसान को मिनख पढ़ते नजर आएंगे। नई शिक्षा नीति के तहत प्राथमिक कक्षाओं में मातृ भाषा में शिक्षा देने की नीति लागू होने से ऐसा होगा। इसके लिए राज्य शैक्षिक अनुसंधान एवं प्रशिक्षण संस्थान ने प्रदेश में संभागवार भाषाई सर्वेक्षण करवाकर स्थानीय भाषा के शब्द कोष तैयार करवाए हैं। शेखावटी के शब्द कोष में शोर को रोला, आदत को बाण, इधर को अठीने, इंतजार को उडीकणों, इकट्ठा को भैळो एवं सांवठो, अध्ययन को पढ़णो, आवास को ठिकाणो, इतना को अतरो, इनकार को नटणों, इसके लिए को इकेपाई एवं अधिक बोलने को लपर-लपर कहा गया है। नई शिक्षा नीति के लिए बच्चों-शिक्षकों की भाषा से शब्दकोष तैयार किया गया है। नई शिक्षा नीति के तहत हुए सर्वेक्षण में प्राथमिक कक्षा के बच्चों की भाषा एवं पढ़ाने वाले शिक्षक की भाषा की जानकारी ली गई थी। इसमें बच्चों के नाम के साथ उनके घर की भाषा, शिक्षक की भाषा, स्कूल का माध्यम, भाषा को समझने एवं बोलने की विद्यार्थियों की क्षम...
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Half wave rectifier | Electronics | Power supply

Half wave rectifier

Rectifier

  • A device which is used to convert alternating current (or voltage) into direct current (or voltage) is known as rectifier
  • The process of converting ac into dc is known as rectification.

Principle of rectifier

  • A diode offers a low resistance in forward bias and a high resistance in reverse bias.
  • It means a very small or practically a zero current flows through the circuit, when diode is reverse biased. This principle is used in the working of rectifier.

Half wave rectifier (HWR)

  • A rectifier which converts only half cycle of input ac into dc is known as half wave rectifier.

  • In this rectifier an alternating voltage E = E0 sin ωt is applied at the primary coil of transformer.
  • The output voltage is always positive, but it does not remain constant with respect to time.
  • The output voltage obtained will be pulsating dc voltage.
  • If Rf = forward dynamic resistance of diode, Rs = resistance of secondary coil of transformer, and RL = load resistance, then
  • Current flowing through RL

Average value of output pulsating current/voltage


Average value of voltage across RL


Root mean square value of pulsating current/voltage

  • For a complete cycle of input, the square root of mean of square of current is root mean square (rms) value of current.


Root mean square value of output voltage


Power supplied to the circuit

  • Input ac power = Power across Rs + Power across diode resistance Rf + Power across RL

Average power supplied to the load

  • Output dc power in load RL

Efficiency of half wave rectifier

  • It is defined as the ratio of the output dc power to the input ac power.
  • η = (output dc power / input ac power) × 100 %

  • By increasing the value of load resistor RL, the value of rectifier efficiency increases.
  • When RL >> R, ηmax = 40.6 %
  • When RL = R, η = 20.3 %

Ripple factor (r)

  • The output voltage or current obtained from rectifier is unidirectional, but its value does not remain constant with time.
  • The pulsation available in the output current or voltage is ripples.
  • Ripple factor gives the measure of smoothing of output voltage or current of a rectifier.
  • r = effective value of output ac component / Average of dc component of output current = Iac / Idc
  • From ac circuit theory

  • Thus half wave rectifier is a poor device for converting ac into dc

Voltage regulation (VR)

  • The strength of maintaining a constant voltage by a rectifier on varying the load resistance is voltage regulation.
  • VR = [(VNL - VFL) / VFL ] × 100%
  • VNL = Output in the absence of load resistance (when RL = ∞)
  • VFL = Output in the presence of load resistance
  • For ideal power supply VR = 0
  • It means in ideal power supply the output voltage should not depend on load.


  • As the value of Idc increases, the value of Edc decreases linearly.

Peak inverse voltage (PIV)

  • The maximum value of voltage which is withstand on the diode, when no current is flowing in the circuit.
  • It is the maximum voltage on the diode in its non-conducting state.
  • For half wave rectifier, PIV = - E0

Frequency component of output voltage or current

  • From Fourier analysis, the output current

  • First term I0 / π represents the dc or average value of current
  • Frequency of second term is equal to the frequency of input ac voltage and its peak value is I0 / 2
  • The other terms represents the harmonics.
To know more about half wave rectifier please visit on https://youtu.be/ZOGVLxLFWxU
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