An ideal ammeter (zero$$ $$resistance) and an ideal voltmeter (infinite$$ $$resistance) are connected as shown. The ammeter reading is given $$asR1=5$$Ω,$$R2=15$$Ω,$$R3=1.25$$Ω and $$E=20$$ V

Question

An ideal ammeter (zero$$ $$resistance) and an ideal voltmeter (infinite$$ $$resistance) are connected as shown. The ammeter reading  is given $$asR1=5$$Ω,$$R2=15$$Ω,$$R3=1.25$$Ω and $$E=20$$ V

Infinity Learn · Accepted Answer

$$Req=R1R2R1+R2($$ Parallel $$combination)$$ ​$$Req=R1+R2$$ Series combination ​Req of the circuit $$=5$$×$$155+15+125100=7520+54=5$$Ω We know that $$I=EReq=205=4$$ A​ Potential difference across $$R1$$ and $$R2$$ are same  (Parallel$$ $$combination) $$I1R1=4$$−$$I1R2$$​⇒$$5I1=4$$−$$I1$$×$$15$$⇒$$I1=12$$−$$3I1$$⇒$$I1=3$$ A​ Thus reading of ammeter $$=3$$ A​ Voltage across $$1.25$$Ω$$=I$$×$$R=4$$×$$1.25=5$$ V (Reading$$ of $$voltmeter)

Kirchoff's Law

Remember concepts with our Masterclasses.

An ideal ammeter (zero resistance) and an ideal voltmeter (infinite resistance) are connected as shown. The ammeter reading is given as $R_{1} = 5 Ω, R_{2} = 15 Ω, R_{3} = 1.25 Ω$ and E=20 V

Ready to Test Your Skills?

free study material

Kirchoff's Law

Remember concepts with our Masterclasses.

An ideal ammeter (zero resistance) and an ideal voltmeter (infinite resistance) are connected as shown. The ammeter reading is given asR1=5Ω,R2=15Ω,R3=1.25Ω and E=20 V

Ready to Test Your Skills?

free study material

An ideal ammeter (zero resistance) and an ideal voltmeter (infinite resistance) are connected as shown. The ammeter reading is given as $R_{1} = 5 Ω, R_{2} = 15 Ω, R_{3} = 1.25 Ω$ and E=20 V