Waec Physics 2008 Past Questions and Answers

Question 41:

• WAEC 2008

A transformer is required to supply 12 V_rms to operate a toy train set from a 240 V_rms. If the number of turns in the in the secondary coil is 100, calculate the number of turns required in the primary coil

A. 5
B. 12
C. 2000
D. 2400

Question 42:

• WAEC 2008

A direct current of 5A flow through a 0.2H inductor. Calculate the energy stored in the inductor

A. 0.5J
B. 1.0J
C. 2.5J
D. 5.0J

Question 43:

• WAEC 2008

Both \(\gamma\)-rays and X-rays i. can be produced by thermionic emission ii. have low frequencies iii. have short wavelengths. Which of the statements above is/are correct?

A. I only
B. Ii only
C. Iii only
D. I and iii only

Question 44:

• WAEC 2008

When a radioactive substance undergoes a beta decay, its

A. Mass number decreases by 1
B. Atomic number decreases by 1
C. Mass number increases by 1
D. Atomic number increases by 1

Question 45:

• WAEC 2008

Nuclear fission is preffered to nuclear fusion in the generation of energy because

A. Very high temperature are required for fusion
B. The raw materials for fusion are easily obtained
C. Energy obtained from fusion is relatively small
D. The by-products of fusion is very dangerous