A.\(x = 6\)
B.\(x = \dfrac{3}{2}\)
C.\(x = \dfrac{5}{2}\)
D.\(x = 10\)

A.hồ tiêu, mía
B.cao su, lạc
C.cà phê, hồ tiêu.
D.lạc, thuốc lá.

A.1,25mH.
B.0,25mH.
C.2,5mH.
D.0,125mH.

A.\(A = {q^2}Et\)
B.\(A = qE\)  
C.\(A = {q^2}E\)  
D.\(A = qEt\)

A.\(x = 12co{\rm{s}}\left( {10\pi t + \frac{\pi }{2}} \right)cm\)
B.\(x = 12co{\rm{s}}\left( {10\pi t - \frac{\pi }{2}} \right)cm\)
C.\(x = 6co{\rm{s}}\left( {10\pi t + \frac{\pi }{2}} \right)cm\)  
D.\(x = 6cos\left( {10\pi t - \frac{\pi }{2}} \right)cm\)

A.\(3,{4.10^{14}}H{\rm{z}}\)
B.\(2,{5.10^{14}}Hz\)  
C.\(2,{5.10^{15}}H{\rm{z}}\)  
D.\(3,{4.10^{15}}H{\rm{z}}\)

A.\(k = 0,2\).  
B.\(k = 10\)
C.\(k = 5\)
D.\(k = 0,1\)

A.0,866.
B.0,525.
C.0,433.
D.0,5.

A.3,55 m/s
B.5,03 m/s.
C.251,33 cm/s.
D.192,26 cm/s.

A.\(\frac{{\sqrt 3 }}{2}\)
B.\(\frac{1}{2}\)
C.\(1\)
D.\(\frac{{\sqrt 2 }}{2}\)