Waec Physics 2005 Past Questions and Answers

Question 46:

• WAEC 2005

Which of the following statements is not a reason for using soft iron in making the core of a transformer? It

A. Retains its magnetism for a long time
B. Is easily magnitised
C. Reduces energy loss due to hysteresis
D. Is easily demagnetised

Question 47:

• WAEC 2005

Beta particles are faster-moving

A. Protons
B. Electrons
C. Neutrons
D. Photons

Question 48:

• WAEC 2005

A process by which two light atoms join to form a new atom of higher atomic mass is

A. Natural radioactivity
B. Nuclear fission
C. Nuclear fusion
D. Chain reaction

Question 49:

• WAEC 2005

Light of energy 5.0 eV falls on a metal of work function 3.0 eV and electrons are emitted, determine the stopping potential. [electronic charge, e = 1.60 x 10⁸ms^-19]

A. 1.7V
B. 2.0V
C. 8.0V
D. 15.0V

Question 50:

• WAEC 2005

The mass of a proton is 1.0089\(\mu\) and that of a neutron is 1.0089\(\mu\). Determine the energy evolved in stabilizing the nucleus of nitrogen of mass number 14 with 7 protons and 7 neutrons. [speed of light = 3.0 x 10⁸ms^-1; 1\(\mu\) = 1.67 x 10^-27kg]

A. 1.710 x 10^-8J
B. 3.131 x 10^-8J
C. 1.476 x 10^-8J
D. 2.332 x 10^-9J