(2010?Lianyungang two model) as shown in the figure, an ideal transformer original, secondary coil turns ratio of 5:1, the original coil voltage u = 311sin100πt (V), the original coil voltage u = 311s

(2010?Lianyungang two model) as shown in the figure, an ideal transformer original, secondary coil turns ratio of 5:1, the original coil voltage u = 311sin100πt (V), the original coil voltage u = 311sin100πt (V), it can be seen that the effective voltage value of the original coil is 220V, so the voltmeter V1 is about 220V. The original coil voltage u = 311sin100πt (V), it can be seen that the original coil of the effective voltage value of 220V, so the voltmeter V1 is about 220V, so A error;

According to the voltage is proportional to the number of turns, by the original, the secondary coil turns ratio of 5:1, it can be seen that the voltage of the secondary coil rms value of 44V. because of the resistor R1 = 20Ω, R2 = 24Ω, so U2 = 24V.

The rms value of the current in the secondary coil is I2=

U

R1+R2

=

44

20+24

A= 1A, so the current in the original coil is I1 =

1

1

5

×1A = 0.02A, so ammeter A2 shows about 1A and ammeter A1 shows about 0.20A, so B is correct and D is wrong;

So choose B.