[{"id":227395,"question":"The peak value of A.C source is 20 A, then its rms value will be.","choices":[{"text":"14.1 A","value":"A"},{"text":"10 A","value":"B"},{"text":"20 A","value":"C"},{"text":"28.2 A","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":227394,"question":"The most common source of an A.C. Voltage is.","choices":[{"text":"Motor","value":"A"},{"text":"Cell","value":"B"},{"text":"Generator","value":"C"},{"text":"Thermo couple","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":227393,"question":"Average value of current and voltage over a complete cycle is.","choices":[{"text":"Positive","value":"A"},{"text":"Negative","value":"B"},{"text":"Zero","value":"C"},{"text":"Infinite","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":227392,"question":"In Pakistan the frequency of A.C. supply is.","choices":[{"text":"50 Hz","value":"A"},{"text":"60 Hz","value":"B"},{"text":"45 Hz","value":"C"},{"text":"70 Hz","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":227391,"question":"The wave form of alternating voltage is a","choices":[{"text":"Cotangent curve","value":"A"},{"text":"Cosine curve","value":"B"},{"text":"Sine curve","value":"C"},{"text":"Tangent curve","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":227390,"question":"The main use of A.C is","choices":[{"text":"Minimum line losses","value":"A"},{"text":"Long distance transmission","value":"B"},{"text":"Stepping up to required voltage only","value":"C"},{"text":"Steeping down to required voltage only","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":227389,"question":"The highest value reached by the voltage or current in one cycle is called.","choices":[{"text":"Peak ot peak value","value":"A"},{"text":"Peak value","value":"B"},{"text":"Instantaneous value","value":"C"},{"text":"Root mean square value","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":227388,"question":"The mean value of A.C. in a cycle is.","choices":[{"text":"1","value":"A"},{"text":"0","value":"B"},{"text":"I2","value":"C"},{"text":"Nil","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":227387,"question":"During each cycle A.C. voltage reaches a peak value.","choices":[{"text":"Once","value":"A"},{"text":"Twice","value":"B"},{"text":"Thrice","value":"C"},{"text":"Four time","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":227386,"question":"Main reason for world wide use of A.C. is","choices":[{"text":"It is cheaper","value":"A"},{"text":"Transmitted","value":"B"},{"text":"Botha a and b","value":"C"},{"text":"Reaches in short time","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":178165,"question":"The circuit in which current and voltage are in phase, the power factor is:","choices":[{"text":"Zero","value":"A"},{"text":"1","value":"B"},{"text":"-1","value":"C"},{"text":"2","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":178164,"question":"An electromagnetic wave goes from air to glass which of the following does not change?","choices":[{"text":"Radio waves","value":"A"},{"text":"X-rays","value":"B"},{"text":"Ultra violet radiation","value":"C"},{"text":"Ultra sond waves","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":178163,"question":"For electromagnetic waves, Maxwell generalized","choices":[{"text":"Gauses law for magnetism","value":"A"},{"text":"Gauses law for eletricity","value":"B"},{"text":"Fradays law","value":"C"},{"text":"Amperes law","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":178162,"question":"An alternating quantity (voltage or current) is completely known if we know its:","choices":[{"text":"Maximum","value":"A"},{"text":"Frequency and phase","value":"B"},{"text":"Effective value","value":"C"},{"text":"Both (a) &amp; (b)","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":178161,"question":"In LR circiut which one of the following statements is correct?","choices":[{"text":"L and R opposes each other","value":"A"},{"text":"R value increases with frequency","value":"B"},{"text":"The inductive reactance increases with frequency","value":"C"},{"text":"The inductive reactance decreases with frequency","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":178160,"question":"An alternating voltage is given by 20 sin 157 t. Th efrequency of alternating voltage is:","choices":[{"text":"50 Hz","value":"A"},{"text":"25Hz","value":"B"},{"text":"100 Hz","value":"C"},{"text":"75 Hz","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":178159,"question":"The phase difference between the current and voltage at resonce is:","choices":[{"text":"0","value":"A"},{"text":"<span style=\"color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 16px;\">π</span>","value":"B"},{"text":"-<span style=\"color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 16px;\">π</span>","value":"C"},{"text":"<span style=\"color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 16px;\">π/2</span>","value":"D"},{"value":"E"}],"correctAnswer":1}]