{"id":26324,"date":"2025-06-19T12:25:49","date_gmt":"2025-06-19T12:25:49","guid":{"rendered":"https:\/\/gaviki.com\/blog\/?p=26324"},"modified":"2025-06-19T12:25:51","modified_gmt":"2025-06-19T12:25:51","slug":"write-the-current-ratio-formula","status":"publish","type":"post","link":"https:\/\/gaviki.com\/blog\/write-the-current-ratio-formula\/","title":{"rendered":"Write the current ratio formula."},"content":{"rendered":"\n

Write the current ratio formula. b) Write the turns ratio formula. c) Write the voltage ratio formula. d) Is the number of secondary turns in a step-up transformer higher than the number of primary turns? True or False. e) Is the number of secondary turns in a step-down transformer lower than the number of primary turns? True or False. Questions f-i are based on the following drawing: s = 1A Primary: 60V (AC) Secondary: f) The value of the primary current is equal to _ amps. 10:1 turns ratio g) The secondary voltage is equal to volts. h) The total power in the primary winding equals __<\/em><\/strong> watts. i) The input winding of a transformer is called the<\/p>\n\n\n\n

The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n

Here are the correct answers and detailed explanations:<\/p>\n\n\n\n

\n\n\n\n

a) Current Ratio Formula:<\/strong> IpIs=NsNp\\frac{I_p}{I_s} = \\frac{N_s}{N_p}Is\u200bIp\u200b\u200b=Np\u200bNs\u200b\u200b<\/p>\n\n\n\n

Where:<\/p>\n\n\n\n

    \n
  • IpI_pIp\u200b is the primary current<\/li>\n\n\n\n
  • IsI_sIs\u200b is the secondary current<\/li>\n\n\n\n
  • NpN_pNp\u200b is the number of turns in the primary coil<\/li>\n\n\n\n
  • NsN_sNs\u200b is the number of turns in the secondary coil<\/li>\n<\/ul>\n\n\n\n

    This formula shows that current is inversely proportional to the number of turns. More turns mean less current, and fewer turns mean more current.<\/p>\n\n\n\n

    \n\n\n\n

    b) Turns Ratio Formula:<\/strong> NpNs=VpVs\\frac{N_p}{N_s} = \\frac{V_p}{V_s}Ns\u200bNp\u200b\u200b=Vs\u200bVp\u200b\u200b<\/p>\n\n\n\n

    This equation relates the number of turns in the primary and secondary windings to the voltages across them. A transformer changes voltage depending on this turns ratio.<\/p>\n\n\n\n

    \n\n\n\n

    c) Voltage Ratio Formula:<\/strong> VpVs=NpNs\\frac{V_p}{V_s} = \\frac{N_p}{N_s}Vs\u200bVp\u200b\u200b=Ns\u200bNp\u200b\u200b<\/p>\n\n\n\n

    Where:<\/p>\n\n\n\n

      \n
    • VpV_pVp\u200b is the primary voltage<\/li>\n\n\n\n
    • VsV_sVs\u200b is the secondary voltage<\/li>\n<\/ul>\n\n\n\n

      Voltage is directly proportional to the number of turns. More turns result in higher voltage.<\/p>\n\n\n\n

      \n\n\n\n

      d) True.<\/strong>
      In a step-up transformer<\/strong>, the secondary<\/strong> winding has more turns<\/strong> than the primary<\/strong> to increase voltage.<\/p>\n\n\n\n

      \n\n\n\n

      e) True.<\/strong>
      In a step-down transformer<\/strong>, the secondary<\/strong> winding has fewer turns<\/strong> than the primary<\/strong> to reduce voltage.<\/p>\n\n\n\n

      \n\n\n\n

      Based on the drawing:<\/h3>\n\n\n\n
        \n
      • Given:<\/strong>\n
          \n
        • Primary voltage Vp=60VV_p = 60VVp\u200b=60V<\/li>\n\n\n\n
        • Turns ratio Np:Ns=10:1N_p : N_s = 10 : 1Np\u200b:Ns\u200b=10:1<\/li>\n\n\n\n
        • Secondary current Is=1AI_s = 1AIs\u200b=1A<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n
          \n\n\n\n

          f) Primary Current = 0.1 A<\/strong><\/p>\n\n\n\n

          Use the current ratio formula: Ip1=110\u21d2Ip=0.1\u2009A\\frac{I_p}{1} = \\frac{1}{10} \\Rightarrow I_p = 0.1 \\, \\text{A}1Ip\u200b\u200b=101\u200b\u21d2Ip\u200b=0.1A<\/p>\n\n\n\n

          \n\n\n\n

          g) Secondary Voltage = 6 V<\/strong><\/p>\n\n\n\n

          Use the voltage ratio formula: VpVs=NpNs=10\u21d260Vs=10\u21d2Vs=6\u2009V\\frac{V_p}{V_s} = \\frac{N_p}{N_s} = 10 \\Rightarrow \\frac{60}{V_s} = 10 \\Rightarrow V_s = 6 \\, \\text{V}Vs\u200bVp\u200b\u200b=Ns\u200bNp\u200b\u200b=10\u21d2Vs\u200b60\u200b=10\u21d2Vs\u200b=6V<\/p>\n\n\n\n

          \n\n\n\n

          h) Power = 6 W<\/strong><\/p>\n\n\n\n

          Power is conserved in an ideal transformer: P=Vs\u00d7Is=6\u00d71=6\u2009WP = V_s \\times I_s = 6 \\times 1 = 6 \\, \\text{W}P=Vs\u200b\u00d7Is\u200b=6\u00d71=6W<\/p>\n\n\n\n

          Also: P=Vp\u00d7Ip=60\u00d70.1=6\u2009WP = V_p \\times I_p = 60 \\times 0.1 = 6 \\, \\text{W}P=Vp\u200b\u00d7Ip\u200b=60\u00d70.1=6W<\/p>\n\n\n\n

          \n\n\n\n

          i) Input Winding = Primary<\/strong><\/p>\n\n\n\n

          The input winding<\/strong> of a transformer is called the primary<\/strong> winding, as it receives the incoming electrical energy.<\/p>\n\n\n\n

          \n\n\n\n

          These relationships show the importance of understanding how voltage, current, and number of turns interact in a transformer.<\/p>\n\n\n\n

          \"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

          Write the current ratio formula. b) Write the turns ratio formula. c) Write the voltage ratio formula. d) Is the number of secondary turns in a step-up transformer higher than the number of primary turns? True or False. e) Is the number of secondary turns in a step-down transformer lower than the number of primary […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-26324","post","type-post","status-publish","format-standard","hentry","category-quiz-questions"],"_links":{"self":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/26324","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/comments?post=26324"}],"version-history":[{"count":1,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/26324\/revisions"}],"predecessor-version":[{"id":26326,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/26324\/revisions\/26326"}],"wp:attachment":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/media?parent=26324"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/categories?post=26324"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/tags?post=26324"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}