Physics, asked by Anonymous, 1 year ago

1}The power factor of a series RL circuit is 1/√2.if the frequency if the applied ac is doubled,the power factor becomes
1)1/√3
2)1/√5
3)1/√7
4)1/√11


2}A circuit has a resistance of emf 200v is appplief to a circuit consisting if a resistance of 40ohm.they r connected in series with an ac source.if the peak value of current is 1A nd the voltage is 220v,the power consumed by the circuit is
1)66w
2)6.6w
3)0.66w
4)33w


kvnmurty: Qn 2... What is 200V?? Can you write correct problem here again..
kvnmurty: Correct statement of qn 2.please
Anonymous: The ques i wrote as it was given sir

Answers

Answered by kvnmurty
33
X_L = ω L
Power factor of a RL A.C. Circuit is given by
   p.f. =  R /√[ R² + X_L²]
         =  1 /√[ 1 + (ω²L²/R²) ]  = 1/√2   given
   =>  ωL/R = 1
 
If  frequency is doubled, then ωL/R becomes twice.
 
   p.f. = 1/√[1 + 4] = 1/√5

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2 ) This problem statement is not clear...


kvnmurty: clik on red heart thanks above pls
Anonymous: 2nd 1 we can solve
kvnmurty: How do u solve it if problem statement is not clear
kvnmurty: Some data is missing
Anonymous: No sir so i too was confused abt it
kvnmurty: how do you accept the line in the answer that R = 30 ohms ? how could you solve qn 2 ? you say you can solve it
kvnmurty: thank you @deeksha for selecting brainliest. that is very nice of you.
Anonymous: U explained it so perfectly sir..
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