Waec Physics 2010 Past Questions and Answers

Question 46:

• WAEC 2010

The resonant frequency of an a.c circuit is 1000 kHz. If each of the capacitance and inductance in the circuit is reduced by 50%, and no other changes are made, the resonant frequency will become

A. 250kHz
B. 750kHz
C. 1000kHz
D. 2000kHz

Question 47:

• WAEC 2010

Eddy currents can be reduced by

A. Using coil of high resistance
B. Winding the coil on a soft iron core
C. Creating holes in the metal plates
D. Using coil of low resistance

Question 48:

• WAEC 2010

an electron moves with a speed of 2.0 x 10⁶ms^-1 in a straight line. Calculate the wave length of the electron wave. [mass of an electron = 9.1 x 10^-31 kg][Planck's constant = 6.6 x 10^-34Js]

A. 3.63 x 10^-19m
B. 6.51 x 10^-9m
C. 4.24 x 10^-8m
D. 7.25 x 10^-8m

Question 49:

• WAEC 2010

Oxidation of the filament in a light bulb is prevented by the introduction of

A. Hydrogen
B. Oxygen
C. Argon
D. Mercury vapour

Question 50:

• WAEC 2010

In a cathode ray tube, the function of the x-plates is to

A. Deflect the electron beam horizontally
B. Deflect the electron beam vertically
C. Reflect the electron beam
D. Generate sinusoid waves