Question

48. A transformer is used to supply a 12-V model train with
power from a 110-V wall plug. The train operates at
50Wofpower.(a)What is the rms current in the secondary coil of the
transformer? (b) What is the rms current in the primary
coil?(c)What is the ratio of the number of primary to secondary
turns? (d) What is the resistance of the train? (e) What is the
resistance seen by the 110-V source?

Answer #2

Data given.

Voltge in primary coil , V1 = 110 V

Voltage in secondary coil, V2 =12 V

Power , P = 50 W

Part (a). Rms Current in secondary coil.

I secondary = power / V2

Is = 50/12 = 4.167 A

Part-b

Rms current in primary coil.

I primary = power / V1

Ip = 50/110 = 0.4545 A

Part-c

The primary is the 110 V side of the transformer, and the secondary is the 12 V side.

The turn ratio is directly proportional to the voltage ratio.

So, N primary / N secondary = 110/ 12

= 9.167

D -

Resistance in of train.

R2 = V2 / Is

= 12/4.167

= 2.87 ohm

Part E

Resistance at source.

R1 = V1/Ip

= 110/0.4545

= 242 ohm

answered by: anonymous

A transformer connected to a 120 −V ac line is to supply 12.0 VV
(rms) to a portable electronic device. The load resistance in the
secondary is 5.20 ΩΩ .
- What should the ratio of primary to secondary turns of the
transformer be, What rms current must the secondary supply?
- What average power is delivered to the load, What resistance
connected directly across the source line (which has a voltage of
120 −V) would draw the same power...

The “power cube” transformer for a portable CD player has an
output of 4.5 V and 500 mA (both rms) when plugged into a 120V/60Hz
outlet. Part A If the primary coil has 1220 turns of wire, how many
turns are on the secondary coil? I found the answer to part A: N=46
turns. Part B What is the peak current in the primary coil?

An ideal step-down transformer has a primary coil of 370 turns
and a secondary coil of 25 turns. Its primary coil is plugged into
an outlet with 115 V(AC), from which it draws an rms current of
0.69 A.
What is the voltage in the secondary coil?
Calculate the rms current in the secondary coil.
Assuming that the transformer secondary is driving a resistive
load, calculate the average power dissipated in the resistor.

a) An ideal step-down transformer has a primary coil of 400
turns and a secondary coil of 14 turns. Its primary coil is plugged
into an outlet with 240 V(AC), from which it draws an rms current
of 0.35 A. What is the voltage in the secondary coil?
b) Calculate the rms current in the secondary coil.
c) Assuming that the transformer secondary is driving a
resistive load, calculate the average power dissipated in the
resistor.

A small transformer to recharge the battery in a cell phone is
plugged into a wall socket that has 120 volts RMS and a maximum
available current of 20 Amps. The secondary coil of the transformer
has 14 turns, and the output voltage of the transformer is 5.5V
(DC). The recharger takes 440mA out from the transformer. Assume
the transformer is ‘ideal’, with and efficiency of 100 percent.
What is the resistance of the battery recharger from the cell
phone?...

An AC adapter for a telephone answering machine uses a
transformer to reduce the line voltage of 120 V to a voltage of
4.00 V. The RMS current delivered to the answering machine is 350
mA. If the primary (input) coil of the transformer has 720 turns,
then how many turns are there on the secondary (output) coil?
What is the power drawn from the electric outlet, if the
transformer is assumed to be ideal?
What is the power drawn...

An AC adapter for a telephone answering machine uses a
transformer to reduce the line voltage of 120 V to a voltage of
4.00 V. The RMS current delivered to the answering machine is 660
mA. If the primary (input) coil of the transformer has 600 turns,
then how many turns are there on the secondary (output) coil?
What is the power drawn from the electric outlet, if the
transformer is assumed to be ideal?
What is the power drawn...

An AC source of rms voltage 50 V and frequency 150 Hz is
connected to the primary coil of a transformer that has 5000 turns
on the primary side and 7500 turns on the secondary side. If the
secondary coil is connected to a 150 ohm load, determine the
current flowing through the primary coil.
0.75 A
1.25 A
0.25 A
0.50 A

An ideal transformer has 100 turns on its primary coil and 200
turns on its secondary coil. If 120 V at 2.0 A is applied to the
primary,
(a) What voltage is present in the secondary?
(b) What current is present in the secondary?
(c) What is the output power?
(d) Is this a step-up or step-down transformer?
(e) Is the input power the same, larger or smaller than the
output power?

A transformer has 500. primary turns and 10.0 secondary turns.
(a) If Vp is 120.V(rms), what is Vs? If the secondary now has a
resistive load of 10.0Ω, what is the current in the (b) secondary
and (c) primary? (Hints: Input power equals the output power.
Express power in terms of voltage and current, then use Faraday’s
Law to relate voltage to number of turns and change of flux. If the
primary and the secondary are connected via a closed...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 5 minutes ago

asked 7 minutes ago

asked 8 minutes ago

asked 16 minutes ago

asked 24 minutes ago

asked 27 minutes ago

asked 45 minutes ago

asked 46 minutes ago

asked 47 minutes ago

asked 57 minutes ago

asked 1 hour ago

asked 1 hour ago