# a 230v/30v with 50Hz transformer that has a primary current of 0.6A which supply's number of 30v and 30 watts halogen light bulb. what is the efficiency?

47,469 results
1. ## physics

A 10uf capacitor is charged from a 30v supply and then connected across an uncharged 50uf capacitor.Calculate a. The final potential difference across the combination b. The final and initial energies

2. ## Physics

In a step-up transformer, which of the following statements is correct? Number of turns in primary is equal to number of turns in the secondary. Number of turns in primary is more than the number of turns in the secondary. Number of turns in primary is

asked by Anonymous on January 29, 2013
3. ## electrical

transformer overheat while taking a shore supply which is the likely cause

asked by dharem on February 12, 2017
4. ## physics

Find the turn ratio in a transformer which deliver a voltage of 120volts in the secondary coil form a primary voltage at 60v. Please someone should help me with this

asked by khalid idris on January 14, 2016
5. ## Physics

Which of the following is correct for a step-down transformer? Number of turns in the primary coil is less than the number of turns in the secondary coil. Step-down transformer increases the voltage from low value to high value. Number of turns in the

asked by Liam on October 22, 2012
6. ## Physics

A model electric train requires 6 V to operate. If the primary coil of its transformer has 240 windings, how many windings should the secondary have if the primary is connected to a 120 V household circuit?

asked by Lauren on November 10, 2009
7. ## physics- magnetism

A step-up transformer used in a car has a potential difference of 10 V across the primary coil with 12 turns. What is the current in the secondary coil of resistance 2.5 Ω if the number of turns in the secondary coil is 54 turns?

asked by marjean on September 14, 2016
8. ## physics

An electric kettle operates at 230V and draws a current of 13A. What would the equivalent current be at the following voltages used in the UK National Grid? Show all your working. a) 33kV (33000V) (4 marks) b) 400kV (4 marks)

asked by anonymous on March 12, 2011
9. ## Circuits 2

For the circuit below, V1 has rms voltage of Vrms=10V. The turn ratio of the primary to secondary side of the transformer is 1:10. If R1 has a value of 20Ω, what is the value of the rms current on the secondary side? Enter your answer in units of Amps.

asked by student on April 9, 2018
10. ## Physics

A transformer consists of 275 primary windings and 834 secondary windings. If the potential difference across the primary coil is 25 V, (a) What is the voltage across the secondary coil? (b) what is the effective load resistance of the secondary coil if it

asked by J on March 18, 2008
11. ## Circuits 2

a circuit with an ideal transformer with a source voltage, Vs=10cos(ωt)V, N1:N2=1:4, and RL=50Ω. What is the magnitude of the current on the primary side of the transformer?

asked by student on April 10, 2018
12. ## Circuits 2

V1 has rms voltage of Vrms=10V. The turn ratio of the primary to secondary side of the transformer is 1:10. If R1 has a value of 20Ω, what is the value of the rms current on the secondary side? what is the value of the rms current on the primary side?

asked by student on April 10, 2018
13. ## physics prob.

An ideal transformer has 50 turns in its primary coil and 250 turns in its secondary coil. 12 V is connected to the primary. a)find the voltage across the secondary coil. b) find the current in a 10-ohms device connected to the secondary. c) find the power

asked by sam on February 14, 2008
14. ## physics

a transformer has 200 turns in its primary coil, the potential difference across the transformer is 220V needs to operate an electrical instrument uses a 110 volts. the number of turns in its secondary coil is: a) 100 turns b) 200 turns c) 110 turns d) 220

asked by help physics on August 25, 2012
15. ## Physics

A step up transformer used in an automobile has a potential difference across the primary of 2200 V and a potential difference across the secondary of 25 V. What is the ratio of the numbers of turns of wire on the primary to the secondary?

asked by 0w0 on April 23, 2020
16. ## physics

A coil takes a current of 10.0 A and dissipates 1410 W when connected to a 230 V, 50 Hz sinusoidal supply. When another coil is connected in parallel with it, the total current taken from the supply is 20.0 A at a power factor of 0.866. Determine the

asked by lolo on August 4, 2015
17. ## Voltage

If a transformer has 3,000 loops in its primary coil and 1,500 loops in its secondary coil, how do I find the voltage in the secondary coil if the voltage in the primary coil is 120V? Is there a formula? HELP, please!

asked by Lynda on April 19, 2010
18. ## physics

A hair dryer uses 10A at 120V. It is used with a transformer in England, where the voltage is 240V. A. What should be the ratio of the turns of the transformer? B. What current will the hair dryer now draw?

asked by Crystal on February 28, 2011
19. ## science

an electric heater draws a current of 10A when connected to a 200 V supply. what current will the heater draw when it is connected to a 220 V supply.

asked by MOSTWWANTED on May 17, 2016
20. ## Chemistry

The input voltage from a generating plant to a transformer is 11,000 V. If the output voltage from the transformer to high-voltage transmission lines is 240,000 V, what is the ratio of secondary to primary turns in this step-up transformer

asked by Austin on May 16, 2019
21. ## physics

please tell me if this is correct, A step-down transformer has 16000 turns on the primary and 95 turns on the secondary. If the rms emf across the secondary coil is 120 V, what is the maximum emf across the primary coil? is the answer 28577.69 V ?

asked by physics on March 17, 2009
22. ## Physics

A transformer is to be used to provide power for a computer disk drive that needs 5.8 V (rms) instead of the 120 V (rms) from the wall outlet. The number of turns in the primary is 414, and it delivers 500 mA (the secondary current) at an output voltage of

asked by ricky on March 22, 2018
23. ## Physics

A soldering iron uses an electric current in a wire to heat the tip. A transformer with 100 turns on the secondary coil provides 54 W at an rms voltage of 26 V. a) How many turns are in the primary coil? b) What is the current in the primary coil?

asked by Bob on March 14, 2011
24. ## physics #26

How dose the current in the secondary of a transformer compare with the current in the primary when the secondary voltage is twice the primary voltage?

asked by tina on February 14, 2008
25. ## Physics

A neighbourhood requires 1.5 x 10^5 w of electricity to power all homes during peak usage times. A step-down transformer is used on the high voltage transmission lines to lower the voltage to 120v for household use. There are 25000 primary coils and 140

asked by Sandara on February 2, 2015
26. ## Sciece

The primary of a step-down transformer connected to a 240 V source has 1000 turns. The secondary has 100 turns. What is the output voltage of this transformer?

asked by Jayla on November 5, 2012
27. ## Physics

Can someone please help me out on this... An ideal transformer has 50 turns in its primary and 250 turns in its secondary. 12 V ac is connected to the primary. Find: a. The volts ac available at the secondary. b. Current in the 10  device connected to

asked by Alex on November 1, 2007
28. ## Physics

A transformer has 25 turns in the primary coil and 200 turns in the secondary coil. If 12 V is connected to the primary coil and a 20-Ω device is connected to the secondary coil, calculate the current in Amperes passing through the device.

asked by Natalie on March 17, 2013
29. ## Physics

there are four individual transformer feeder having connected loads of 250 kva, 300 kva, 350 kva, demand factor of these are 80%, 70%, 75% and 90% respectively diversity factor is 1.6 find the total demand of load and size of transformer required to supply

asked by V Roy on May 2, 2020
30. ## Physics

In Europe, the standard voltage is 230 V (rms), AC, and 50 cycles/s. Suppose you take your 5.00 W electric razor to Rome and plug it into the receptacle (with an adapter to fit the receptacle but not to change the voltage). (The standard voltage in the

asked by Alyssa on March 26, 2016
31. ## Physics

A step-up transformer has 500 turns on its primary and 1000 turns on its secondary. When the primary is connected to 100 V and the secondary is connected to a floodlight that draws 4 A, what is the power output?

asked by paul on April 10, 2017
32. ## Physics

A battery with voltage drop of 120V is connected in a ciruit containing both series and parallel. Moving in a clockwise direction. R1= 3 ohms. Suddenly there is a connection of point A to point B. In between these two points is a parallel circuit with R2=

asked by Andrea on March 26, 2008
33. ## physics

the turn ratio of transformer is 1:10.A battery of 12v is connected to the primary coil,what is the voltage drop across the secodary coil

asked by balu on January 22, 2016
34. ## physics

a 230v/30v with 50Hz transformer that has a primary current of 0.6A which supply's number of 30v and 30 watts halogen light bulb. what is the efficiency?

asked by mike on December 16, 2018
35. ## physics

a 230v/30v with 50Hz transformer that has a primary current of 0.6A which supplys number of 30v and 30 watts halogen light bulb. find the maximum number of bulb can operate. assume that its an ideal transformer and can operate within its rated value.

asked by mike on December 12, 2018
36. ## Physics

a 230v/30v with 50Hz transformer that has a primary current of 0.6A which supplys number of 30v and 30 watts halogen light bulb. find the maximum number of bulb can operate. assume that its an ideal transformer and can operate within its rated value.

asked by Mike on December 12, 2018
37. ## Electricity

RCL Circuits electricity!? A 50V, 50Hz supply is connected to a series circuit consisting of a resistance, a 20mH inductor and a capacitor. a) Find the value of the capacitance and the power dissipated in the circuit when: (i) The current has a magnitude

asked by Claire on January 21, 2010
38. ## Physics

A step-down transformer operates a 2400v and supplied a current of 60A. The turns ratio of the transformer is 1/24. Calculate a)secondary voltage b)primary current c)power output if the transformer is 100% efficient?

asked by Anonymous on April 28, 2020
39. ## Physics

A step-down transformer operates a 2400v and supplied a current of 60A. The turns ratio of the transformer is 1/24. Calculate a)secondary voltage b)primary current c)power output if the transformer is 100% efficient?

asked by Sannu Xeno on September 22, 2019
40. ## Physics

A step down transformer operates a 2400 volt lines and supplies a current of 60A.The turn ratio of the transformer is 1:24.calculate the secondary voltage, the primary current and the power output, if the transformer is 100% efficient

asked by Ayo on February 15, 2020
41. ## Physics

The output voltage and current of a transformer are determined by the A. number of turns in the primary and secondary coils. B. ferromagnetic material of the rings connecting the coils. C. strength of the DC current in the primary coil. D. direction of the

asked by Saif on January 24, 2017
42. ## Physics

Suppose there are two transformers between your house and the high-voltage transmission line that distributes the power. In addition, assume your house is the only one using electric power. At a substation the primary of a step-down transformer (turns

asked by Busker on October 22, 2012
43. ## Science

A coil of inductance 0.04henry and negligible resistance is connected in parallel with a 10ohms resistor, across a 240volts supply of frequency 50hz. Calculate:1) the current through the resistance, 2) the current through the coil, 3)the supply current,

asked by Vincent on June 10, 2018
44. ## physics

1. x-ray machine operates at 200 kv with a current of 10 mA. The power mus be produced by a transformer which raises the voltage from 220 volts to 200 kilovolts. The power going into and out of the transformer is the same. How much current must flow in the

asked by mitch on November 17, 2006
45. ## physics

consider a series R-C circuit consisting of a 30 ohm resistor and 20*10^-6F capacitor connected to a 100V,50Hz power supply.find the magnitude of the current and the angle by which the current leads the voltage.

asked by ruth on April 4, 2016
46. ## physics

The function of those little black transformers that clog your power strips is to step down line voltage to run small electronic gadgets. Suppose a fax machine uses an ideal transformer with a primary voltage of 120 V and primary windings. If the secondary

asked by seanmarch58 on July 27, 2014
47. ## Physics - Transformer in AC

A soldering iron uses an electric current in a wire to heat the tip. A transformer with 100 turns on the secondary coil provides 54 W at an rms voltage of 26 V. a) How many turns are in the primary coil? b) What is the current in the primary coil?

asked by Bob on March 14, 2011
48. ## MONGU COLLEGE

A resistor of 15 ohms and an inductor of 4H and capacitor of 25 micro F are connected in series across 230V AC supply calculate. a.The frequency b.current c.voltage drop or pd across inductance.

asked by barotseland network on March 5, 2013
49. ## science

A step-up transformer has 120 turns on its primary coil. It has 1150 turns on its secondary coil. The primary circuit is supplied with an alternating current at 120 V. The current in the secondary circuit is 2.4 A. What current is in the primary circuit?

asked by martin on April 3, 2008
50. ## physics

A step-up transformer has 40 turns on its primary and 100 turns on its secondary. When the primary is supplied with an alternating current at 140 V, what is the voltage across the secondary?

asked by Anonymous on April 10, 2017
51. ## Science

A transformer has 60 turns in the primary and 1200 turns in secondary.if the primary voltage is 500 V what will be the secondary voltage be? What will the current be if the primary if the secondary carries 2.0 A

asked by Hannah on September 18, 2016
52. ## math

A 300 kVA transformer has a primary winding resistance of 0.4 Ω and a secondary winding resistance of 0.0015 Ω. The iron loss is 2 kW and the primary and secondary voltages are 4 kV and 200 V respectively. If the power factor of the load is 0.78,

asked by Anonymous on May 18, 2013
53. ## Physics

A transformer has 120 V across the 100-turn primary coil and has 5 turns in the secondary coil. If the current in the primary coil is 0.1 A, how much power is dissipated in the secondary coil?

asked by elliot on April 10, 2017
54. ## physics

A transformer with 360 turns in its primary coil and 18 turns in its secondary coil is designed to delivered an average power of 1400 W with a maximum voltage of 60 V. What is the maximum current in the primary coil?

asked by Sonia on August 3, 2011
55. ## physics

The primary coil of a transformer is connected to a standard wall socket. A resistance R is connected across the secondary coil. The resistance across the secondary coil is increased. What happens to the current in the primary coil, and what happens to the

asked by josh on July 28, 2010
56. ## Physics

The primary coil of a transformer has 739 loops. The secondary coil has 953,677 loops. The primary coil has a 76 A current and 58 V. b.) Determine the power of the primary coil. W c.) Assuming no losses, determine the power of the secondary coil. W d.)

asked by Cameron on December 1, 2018
57. ## Physics

The primary of a step-down transformer connected to a 240 V source has 1000 turns. The secondary has 100 turns. What is the output voltage of this transformer?

asked by Natalie on March 17, 2013
58. ## Physics - Help!!!

I am having trouble understanding transformers!! Here is the problem I have to solve: A protable CD player requires 12 volts to operate. A transformer allows the device to be powered from a 120-volt outlet. If the primary has 500 turns, how many turns

asked by Justin on May 29, 2012
59. ## Physic

an someone please help me out on this... An ideal transformer has 50 turns in its primary and 250 turns in its secondary. 12 V ac is connected to the primary. Find: 1. The volts ac available at the secondary 2. Current in the 10  device connected to t

asked by Ollie on November 2, 2007
60. ## transformers

A resistive load of 2 k is connected across the secondary windings of a 25:1 transformer. If the primary voltage is 50 V AC, what will be the secondary current? im getting 2mA but the correct answer is 1 mA please help

61. ## Physics problem

A transformer has 50 turns in its primary coil and 250 turns in its secondary coil. 12V is connected to the primary. a. Find the voltage across the secondary coil. b. Find the current in a 10 ohm device connected to the secondary. c. Find the power

asked by Peyton on February 15, 2008
62. ## Physics

A transformer has a secondary voltage of 12 V. The primary voltage is 60V. The number of turns in the secondary is 100. How many turns are in the primary? I keep getting 200 using the equation Vs/Vp= Ns/Np the answer is 500... what am i doing wrong

asked by TJ on August 3, 2009
63. ## Physics 2

Explain briefly the workings of electrical transformer, both step-up and step-down In a step-up transformer, compare the secondary voltage and current to the corresponding primary values. Explain briefly how transformers minimize losses in long distance

asked by seanmarch58 on July 28, 2014
64. ## Physics

a transformer with 600 turns in the primary coil is connected to a 120v AC source. If the transformer is to have (3) separate secondary coils that need to give a) 2.5v, b) 6.0v, and c) 450v, then how many turns should each coil have?

asked by Jay on May 10, 2013
65. ## Physics

An electric lamp has the following markings 230V. 250W, How long would it take the lamp to use one kilowatt-hour when connected to a 230V mains?

asked by Majiri on September 17, 2017
66. ## Physics

I am doing a Transformer experiment and I don't understand how the max voltage of the secondary is always the same while the max voltage of the primary is always changing at different transformer ratio. Can somebody explain that?

asked by Anonymous on March 30, 2020
67. ## physics

A step-down transformer has a turns ratio of 1:10 and its primary is connected across the terminals of a standard 120 V wall socket. A 330 ohm resistor is connected across the secondary of this transformer. What power P is dissipated in the resistor?

asked by josh on July 28, 2010
68. ## physics

An electric kettle operates at 230V and draws a current of 13A. What would the equivalent current be at the following voltages used in the UK National Grid? Show all your working. a) 33kV (33000V) (4 marks) b) 400kV (4 marks)

asked by anonymous on March 12, 2011
69. ## Physics

A transformer has 25 turns in the primary coil and 200 turns in the secondary coil. If 12 V is connected to the primary coil and a 20-Ù device is connected to the secondary coil, calculate the current in Amperes passing through the device.

asked by Layla on November 5, 2012
70. ## Physical Science Help!

A transformer has 25 turns in the primary coil and 200 turns in the secondary coil. If 12 V is connected to the primary coil and a 20-Ù device is connected to the secondary coil, calculate the current in Amperes passing through the device

asked by Carleigh on November 5, 2012
71. ## Physics

This question really has me stumped and I don't know why, I seem to have forgotten the process . . . A model electric train requires 6 V to operate. If the primary coil of its transformer has 240 windings, how many windings should the secondary have if the

asked by Melinda on November 1, 2007
72. ## physics. help!

An appliance transformer-converter is plugged into a 120 volt AC house outlet. The primary coil has 200 windings of copper wire. The secondary coil has 15 windings of wire. Calculate the voltage output of the transformer-converter.

asked by LL on June 24, 2012
73. ## physics

An appliance transformer-converter is plugged into a 120 volt AC house outlet. The primary coil has 200 windings of copper wire. The secondary coil has 15 windings of wire. Calculate the voltage output of the transformer-converter.

asked by LL on June 24, 2012
74. ## Physics

A video game console operates potential difference of 12.00 V as shown in fig. The potential difference supplied by the power receptacle is 120 V AC. A transformer is used to convert one voltage to the other. If the secondary coil of the transformer (the

asked by Learner on January 14, 2018
75. ## Physics

A 240volts is applied to a primary coil of a step up transformer. What is the ratio of the secondary turn to the primary turns, if the voltage available at the secondary coil is 360volts.?

asked by Samba mambo on November 3, 2019
76. ## Physics

An ideal transformer has 50 turns in its primary and 250 turns in its secondary. 12 V ac is connected to the primary. Find: Power suppled to the secondary?

asked by Lauren on November 10, 2009
77. ## Science

The ratio of Secondary Turns to Primary In a Transformer is 3 if the EMF In the Secondary Coil Is 600Volts Find The EMF Of Primary

asked by Basha on February 25, 2016
78. ## Science

True or False: The input current to a transformer is direct current.

asked by Fifilafoop on May 23, 2013
79. ## physics

Three similar ideal cells (no internal resistances) supply current of 0.5 Ampere to a 10 Ohms resistor when they are in the parallel.How much current will they supply to the same risistor when they are connected in series aiding?

asked by nitz on September 30, 2012
80. ## physics

Three similar ideal cells (no internal resistances) supply current of 0.5 Ampere to a 10 Ohms resistor when they are in the parallel.How much current will they supply to the same risistor when they are connected in series aiding?

asked by nitz on September 30, 2012
81. ## Electrical

A certain load takes 10kW at 0.5pf lagging when connected to a 230V, 60Hz source. The supply company charges a penalty when the power factor fall below 0.8. What size of capacitor must be used in order to avoid penalty?

asked by Jiya on May 2, 2016
82. ## Electromagnetic Iduction

Neon sign require about 12,000 V for their operation. What should be the ratio of the number of loops in the secondary to the number of loops in the primary for a neon-sign transformer that operates off 120 V lines? Nprimary/Nsecondary=

83. ## Electrotechnics N4

a circuit with 3 resisters {9 ohms 10 ohms and 12 ohms} connected in parallel with the source 150v\50HZ.use kitchoffs law to find the current of the circuit and the current across each resister?

asked by hlehle on July 12, 2011
84. ## electrical

A 35 kVA transformer supplies a load of 12 kW at a power factor of 0.45 lagging. Find the percentage of full load the transformer is carrying. If additional unity power factor loads are to be served with the same transformer, how many kW may be added

asked by ram on January 13, 2012
85. ## physical science

The primary voltage is still 120 V and the number of primary turns = 60, but now the power in the primary side is 3000 Watts and there is a 120 ohm resistor connected to the secondary. Find the current in the resistor, and the secondary voltage and #

asked by brit on April 4, 2012
86. ## Physics

During a 74-ms interval, a change in the current in a primary coil occurs. This change leads to the appearance of a 4.6-mA current in a nearby secondary coil. The secondary coil is part of a circuit in which the resistance is 12 Ù. The mutual inductance

asked by Anonymous on March 7, 2013
87. ## science past year

1.1. A resitance of 1.5ohm is connected in parallel with a resistance of 3 ohm. This combination is connected in series with a resistance of unknown resistance of value R. The circuit is then connected acress a 10 V supply. Calculate: 1.1.1. The value of

asked by kamil on March 10, 2015
88. ## Science

Alternating current going into a transformer has 200 volts. The current coming out has 20 volts. How many loops of wire might each coil have?

asked by Shawn on February 6, 2014
89. ## Transformers

Two 6600/ 250 V transformers have the following short circuited characteristics: Applied voltage 200 V, current 30 A, power input 1200 W for one of the transformers; the corresponding data for other transformer being 120 V, 20 A and 1500 W. All the values

asked by B .N on April 5, 2015
90. ## Physics- Help!!

A step-up transformer is used on a 100 V line to increase the potential difference to 1200 V. If the primary has 120 turns, then what is the number of turns in the secondary coil? 1440 turns 1000 turns 100 turns 10 turns Thanks!!!!!

asked by Ellie on June 9, 2016
91. ## physhcs

An A.c circuit consist of 3uf capacitor and 500ohm resistor in series. If the current voltage applied is 12v and frequency 50Hz. Calculate 1. Current through the circuit 2. Voltage accross the capacitor 3 phase angle 4. Average power supplied 5. Power

asked by ogunleye seun on July 17, 2013
92. ## physics/science

An A.c circuit consist of 3uf capacitor and 500ohm resistor in series. If the current voltage applied is 12v and and frequency 50Hz. Calculate 1. Current though the circuit 2. Voltage accross the capacitor 3 phase angle 4 average power supplied 5 power

asked by ogunleye seun on July 17, 2013
93. ## Physics

A transformer consists of 275 primary windings and 834 secondary windings. If the potential difference across the primary coil is 25 V, (a) What is the voltage across the secondary coil? (b) what is the effective load resistance of the secondary coil if it

asked by J on March 18, 2008
94. ## physics

An electrical power plant generates electricity with a current of 50A and a potential difference of 20,000 V. In order to minimize the power losses due to the high current heating up the line, a transformer steps up the potential difference to 500,000 V

asked by Anonymous on April 12, 2015
95. ## physics 2

the primary coil of a transformer has N1 = 375 turns, and its secondary coil has N2 = 1,875 turns. If the input voltage across the primary coil is Δv = (120 V)sin ωt, what rms voltage is developed across the secondary coil?

asked by monica on March 22, 2018
96. ## physics#30

Why dosen't a transformer work with direct current? why is ac required?

asked by tina on February 14, 2008
97. ## USA PoliScience - HELP FAST

When the Fed was created in 1913, a. it had no role in the management of the nation's economy. b. it was restricted to providing emergency loans to financial institutions. c. it adhered to a strictly supply-side policy focus. d. its primary economic

asked by HM on October 5, 2011
98. ## Physics

An ideal transformer is needed to step the voltage down from 400V to 115V. The primary has 400 turns. How many turns would be necessary on the secondary side?

asked by Crystal on March 1, 2011
99. ## physics

Two resistances 2omega and 3omega are in parallel. The combination is in series with 15omega resistance and a power supply of voltage V. There is a current of 3omega resistance. What are the values of the current and votage across the power supply (a)3a

asked by favour on August 25, 2013
100. ## Physics

A transformer has 3000 loops in its primary coil and 1500 loops in its secondary coil. What is the voltage in the secondary coil if the voltage in the primary coil is 120 V??? ***PLEASE explain how you get the answer*** thank you:)

asked by farhana on April 18, 2011