05. Dynamo, Transformer Inductance
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Alternating Current

155370 A transformer is used to light a $100 \mathrm{~W}$ and 110 $\mathrm{V}$ lamp from a $220 \mathrm{~V}$ mains. If the main current is $0.5 \mathrm{~A}$, the efficiency of the transformer is approximately

1 $30 \%$
2 $50 \%$
3 $90 \%$
4 $10 \%$
AIPMT- 2007
Alternating Current

155371 In a transformer 220 AC voltage is increased to $2200 \mathrm{~V}$. If the number of turns in the secondary are 2000 , then find the number of turns in the primary:

1 200
2 100
3 50
4 20
AP EAPCET-12.07.2022
Alternating Current

155372 A transformer operating at primary voltage 8 $\mathrm{kV}$ and secondary voltage $160 \mathrm{~V}$ serves a load of $80 \mathrm{~kW}$. Assuming the transformer to be ideal with purely resistive load and working on unity power factor, the loads in the primary and secondary circuit would be

1 $800 \Omega$ and $1.06 \Omega$
2 $10 \Omega$ and $500 \Omega$
3 $800 \Omega$ and $0.32 \Omega$
4 $1.06 \Omega$ and $500 \Omega$
JEE Main-28.07.2022
Alternating Current

155373 A cell phone charger consists of a stepdown transformer to convert $A C$ voltage of $120 \mathrm{~V}$ to AC voltage of $5.0 \mathrm{~V}$. If the secondary coil contains 30 turns and charger supplies $720 \mathrm{~mA}$, calculate the current in the primary coil.

1 $12 \mathrm{~mA}$
2 $30 \mathrm{~mA}$
3 $85 \mathrm{~mA}$
4 $160 \mathrm{~mA}$
TS EAMCET 31.07.2022
Alternating Current

155375 A step down transformer connected to an AC mains supply of $220 \mathrm{~V}$ is made to operate at $11 \mathrm{~V}, 44 \mathrm{~W}$ lamp. Ignoring power losses in the transformer, what is the current in the primary circuit ?

1 $0.2 \mathrm{~A}$
2 $0.4 \mathrm{~A}$
3 $2 \mathrm{~A}$
4 $4 \mathrm{~A}$
NEET- 2021
NEET DIGITAL LIBRARY
Alternating Current

155370 A transformer is used to light a $100 \mathrm{~W}$ and 110 $\mathrm{V}$ lamp from a $220 \mathrm{~V}$ mains. If the main current is $0.5 \mathrm{~A}$, the efficiency of the transformer is approximately

1 $30 \%$
2 $50 \%$
3 $90 \%$
4 $10 \%$
AIPMT- 2007
Alternating Current

155371 In a transformer 220 AC voltage is increased to $2200 \mathrm{~V}$. If the number of turns in the secondary are 2000 , then find the number of turns in the primary:

1 200
2 100
3 50
4 20
AP EAPCET-12.07.2022
Alternating Current

155372 A transformer operating at primary voltage 8 $\mathrm{kV}$ and secondary voltage $160 \mathrm{~V}$ serves a load of $80 \mathrm{~kW}$. Assuming the transformer to be ideal with purely resistive load and working on unity power factor, the loads in the primary and secondary circuit would be

1 $800 \Omega$ and $1.06 \Omega$
2 $10 \Omega$ and $500 \Omega$
3 $800 \Omega$ and $0.32 \Omega$
4 $1.06 \Omega$ and $500 \Omega$
JEE Main-28.07.2022
Alternating Current

155373 A cell phone charger consists of a stepdown transformer to convert $A C$ voltage of $120 \mathrm{~V}$ to AC voltage of $5.0 \mathrm{~V}$. If the secondary coil contains 30 turns and charger supplies $720 \mathrm{~mA}$, calculate the current in the primary coil.

1 $12 \mathrm{~mA}$
2 $30 \mathrm{~mA}$
3 $85 \mathrm{~mA}$
4 $160 \mathrm{~mA}$
TS EAMCET 31.07.2022
Alternating Current

155375 A step down transformer connected to an AC mains supply of $220 \mathrm{~V}$ is made to operate at $11 \mathrm{~V}, 44 \mathrm{~W}$ lamp. Ignoring power losses in the transformer, what is the current in the primary circuit ?

1 $0.2 \mathrm{~A}$
2 $0.4 \mathrm{~A}$
3 $2 \mathrm{~A}$
4 $4 \mathrm{~A}$
NEET- 2021
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Alternating Current

155370 A transformer is used to light a $100 \mathrm{~W}$ and 110 $\mathrm{V}$ lamp from a $220 \mathrm{~V}$ mains. If the main current is $0.5 \mathrm{~A}$, the efficiency of the transformer is approximately

1 $30 \%$
2 $50 \%$
3 $90 \%$
4 $10 \%$
AIPMT- 2007
Alternating Current

155371 In a transformer 220 AC voltage is increased to $2200 \mathrm{~V}$. If the number of turns in the secondary are 2000 , then find the number of turns in the primary:

1 200
2 100
3 50
4 20
AP EAPCET-12.07.2022
Alternating Current

155372 A transformer operating at primary voltage 8 $\mathrm{kV}$ and secondary voltage $160 \mathrm{~V}$ serves a load of $80 \mathrm{~kW}$. Assuming the transformer to be ideal with purely resistive load and working on unity power factor, the loads in the primary and secondary circuit would be

1 $800 \Omega$ and $1.06 \Omega$
2 $10 \Omega$ and $500 \Omega$
3 $800 \Omega$ and $0.32 \Omega$
4 $1.06 \Omega$ and $500 \Omega$
JEE Main-28.07.2022
Alternating Current

155373 A cell phone charger consists of a stepdown transformer to convert $A C$ voltage of $120 \mathrm{~V}$ to AC voltage of $5.0 \mathrm{~V}$. If the secondary coil contains 30 turns and charger supplies $720 \mathrm{~mA}$, calculate the current in the primary coil.

1 $12 \mathrm{~mA}$
2 $30 \mathrm{~mA}$
3 $85 \mathrm{~mA}$
4 $160 \mathrm{~mA}$
TS EAMCET 31.07.2022
Alternating Current

155375 A step down transformer connected to an AC mains supply of $220 \mathrm{~V}$ is made to operate at $11 \mathrm{~V}, 44 \mathrm{~W}$ lamp. Ignoring power losses in the transformer, what is the current in the primary circuit ?

1 $0.2 \mathrm{~A}$
2 $0.4 \mathrm{~A}$
3 $2 \mathrm{~A}$
4 $4 \mathrm{~A}$
NEET- 2021
For More Updates join with Us
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Alternating Current

155370 A transformer is used to light a $100 \mathrm{~W}$ and 110 $\mathrm{V}$ lamp from a $220 \mathrm{~V}$ mains. If the main current is $0.5 \mathrm{~A}$, the efficiency of the transformer is approximately

1 $30 \%$
2 $50 \%$
3 $90 \%$
4 $10 \%$
AIPMT- 2007
Alternating Current

155371 In a transformer 220 AC voltage is increased to $2200 \mathrm{~V}$. If the number of turns in the secondary are 2000 , then find the number of turns in the primary:

1 200
2 100
3 50
4 20
AP EAPCET-12.07.2022
Alternating Current

155372 A transformer operating at primary voltage 8 $\mathrm{kV}$ and secondary voltage $160 \mathrm{~V}$ serves a load of $80 \mathrm{~kW}$. Assuming the transformer to be ideal with purely resistive load and working on unity power factor, the loads in the primary and secondary circuit would be

1 $800 \Omega$ and $1.06 \Omega$
2 $10 \Omega$ and $500 \Omega$
3 $800 \Omega$ and $0.32 \Omega$
4 $1.06 \Omega$ and $500 \Omega$
JEE Main-28.07.2022
Alternating Current

155373 A cell phone charger consists of a stepdown transformer to convert $A C$ voltage of $120 \mathrm{~V}$ to AC voltage of $5.0 \mathrm{~V}$. If the secondary coil contains 30 turns and charger supplies $720 \mathrm{~mA}$, calculate the current in the primary coil.

1 $12 \mathrm{~mA}$
2 $30 \mathrm{~mA}$
3 $85 \mathrm{~mA}$
4 $160 \mathrm{~mA}$
TS EAMCET 31.07.2022
Alternating Current

155375 A step down transformer connected to an AC mains supply of $220 \mathrm{~V}$ is made to operate at $11 \mathrm{~V}, 44 \mathrm{~W}$ lamp. Ignoring power losses in the transformer, what is the current in the primary circuit ?

1 $0.2 \mathrm{~A}$
2 $0.4 \mathrm{~A}$
3 $2 \mathrm{~A}$
4 $4 \mathrm{~A}$
NEET- 2021
NEET DIGITAL LIBRARY
Alternating Current

155370 A transformer is used to light a $100 \mathrm{~W}$ and 110 $\mathrm{V}$ lamp from a $220 \mathrm{~V}$ mains. If the main current is $0.5 \mathrm{~A}$, the efficiency of the transformer is approximately

1 $30 \%$
2 $50 \%$
3 $90 \%$
4 $10 \%$
AIPMT- 2007
Alternating Current

155371 In a transformer 220 AC voltage is increased to $2200 \mathrm{~V}$. If the number of turns in the secondary are 2000 , then find the number of turns in the primary:

1 200
2 100
3 50
4 20
AP EAPCET-12.07.2022
Alternating Current

155372 A transformer operating at primary voltage 8 $\mathrm{kV}$ and secondary voltage $160 \mathrm{~V}$ serves a load of $80 \mathrm{~kW}$. Assuming the transformer to be ideal with purely resistive load and working on unity power factor, the loads in the primary and secondary circuit would be

1 $800 \Omega$ and $1.06 \Omega$
2 $10 \Omega$ and $500 \Omega$
3 $800 \Omega$ and $0.32 \Omega$
4 $1.06 \Omega$ and $500 \Omega$
JEE Main-28.07.2022
Alternating Current

155373 A cell phone charger consists of a stepdown transformer to convert $A C$ voltage of $120 \mathrm{~V}$ to AC voltage of $5.0 \mathrm{~V}$. If the secondary coil contains 30 turns and charger supplies $720 \mathrm{~mA}$, calculate the current in the primary coil.

1 $12 \mathrm{~mA}$
2 $30 \mathrm{~mA}$
3 $85 \mathrm{~mA}$
4 $160 \mathrm{~mA}$
TS EAMCET 31.07.2022
Alternating Current

155375 A step down transformer connected to an AC mains supply of $220 \mathrm{~V}$ is made to operate at $11 \mathrm{~V}, 44 \mathrm{~W}$ lamp. Ignoring power losses in the transformer, what is the current in the primary circuit ?

1 $0.2 \mathrm{~A}$
2 $0.4 \mathrm{~A}$
3 $2 \mathrm{~A}$
4 $4 \mathrm{~A}$
NEET- 2021