2004 - WAEC Physics Past Questions and Answers - page 5
41
Calculate the energy stored in a 20\(\mu F\) capacitor. If the p.d between the plates is 40V
A
3.2 x 10-2J
B
1.6 x 10-2J
C
8.0 x 10-4J
D
4.0 x 10-4J
Ask EduPadi AI for a detailed answer
Share this question
42
Given that the gravitational constant is G. Newton's universal law of gravitation states that the force of attraction between two masses M1 and M2 separation by a distance r is
A
\(Gr^2 M_1M_2\)
B
\(Gr M_1M_2\)
C
\(\frac{GM_1 M_2}{r^2}\)
D
\(\frac{GM_1 M_2}{r}\)
Ask EduPadi AI for a detailed answer
Share this question
43
A charge of 1.6 x 10-10C is placed in a uniform electric field of intensity 2.0 x 105 NC-1. calculate the magnitude of the electric force exerted on the change
A
3.2 x 105N
B
1.8 x 105N
C
3.2 x 10-5N
D
1.8 x 10-5N
Ask EduPadi AI for a detailed answer
Share this question
44
Which of the following statements is not correct?
A
a magnetic field is a region in which a magnetic force will be detected
B
a magnetic line of force is a path along which a magnetic fields are scalar quantities it were free
C
magnetic fields are scalar quantities
D
neutral point are obtained where the earth's magnetic force is exactly equal and opposite to that due to a magnet
Ask EduPadi AI for a detailed answer
Share this question
45
The main function of the mouth piece of a telephone is that it converts sound energy to
A
mechanical energy
B
electrical energy
C
chemical energy
D
thermal energy
Ask EduPadi AI for a detailed answer
Share this question
46
An atom is normally electrically neutral because the
A
number of electrons is equal to the number of protons
B
number of electrons is equal to the number of neutrons
C
number of protons is equal to the number of neutrons
D
electrons of the atom are buried deeply in the nucleus
Ask EduPadi AI for a detailed answer
Share this question
47
In which of the following devices is the principle of photoelectric effect not applicable?
A
close-circuit television camera
B
burglar alarm
C
solar cells
D
periscope
Ask EduPadi AI for a detailed answer
Share this question
48
Which of the following statements about X-rays is not correct? They
A
are electromagnetic waves
B
can be used to study crystal lattice
C
can destroy living cells
D
are produced from the nucleus of an atom
Ask EduPadi AI for a detailed answer
Share this question
49
A radioactive substance has a half-life of 3 days. If a mass of 1.55g of this substance is left after decaying for 15 days, determine the original value of the mass
A
49.6g
B
37.2g
C
24.8g
D
12.4g
Ask EduPadi AI for a detailed answer
Share this question
50
Which of the following representations is correct for an atom X with 28 electrons and 30 neutrons?
A
\(^{30}_{28} X\)
B
\(^{28}_{30} X\)
C
\(^{58}_{30} X\)
D
\(^{58}_{28} X\)
Ask EduPadi AI for a detailed answer
Share this question