A.40B.
B.40dB.
C.80B.
D.80dB.

A.\(0,5\pi {\rm{ }}cm\)
B.\(2\sqrt 2 cm\)
C.2cm
D.\(5\pi {\rm{ }}cm\)

A.\({N_2} > {N_1}\).
B.\({N_2} = {N_1}\).
C.\({N_2} < {N_1}\).
D.\({N_2}{N_1} = 1\).

A.33
B.25
C.15
D.35

A.\(i = \sqrt 3 \cos \left( {100\pi t - \frac{\pi }{6}} \right)\,\,\left( A \right)\).
B.\(i = \sqrt 3 \cos \left( {100\pi t + \frac{\pi }{6}} \right)\,\,\left( A \right)\).
C.\(i = 2\sqrt 3 \cos \left( {100\pi t + \frac{\pi }{6}} \right)\,\,\left( A \right)\).
D.\(i = 2\sqrt 3 \cos \left( {100\pi t - \frac{\pi }{6}} \right)\,\,\left( A \right)\).

A.10 cm.
B.8 cm.
C.14 cm.
D.12 cm.

A.\(\frac{{{C_1}}}{3}\).
B.3C1.
C.\(\sqrt 3 {C_1}\).
D.\(\frac{{{C_1}}}{{\sqrt 3 }}\).

A.440 V.
B.4400V.
C.110 V.
D.11 V.

A.1,6 m/s.
B.0,6 m/s.
C.0,4 m/s.
D.0,8 m/s.

A.4.10-6 J.
B.5.10-6 J.
C.2.10-6 J.
D.3.10-6 J.