The diagram above illustrates two charged bodies, X and Y separated by a distance r. Each body has charge q and mass m. Which of the following statements about the electrostatic force \(F_{e}\) and gravitational force \(F_{g}\) acting between the bodies is correct?
- A. \(F_{e}\) is attraction while \(F_{g}\) is repulsion
- B. Both \(F_{e}\) and \(F_{g}\) are that of repulsion
- C. Both \(F_{e}\) and \(F_{g}\) is that of attraction
- D. \(F_{e}\) is repulsion while \(F_{g}\) is attraction
The main reason why a.c. is transmitted at very high voltage and low current is that
- A. flows faster through the conductor
- B. can be stepped down
- C. is cheaper to generate
- D. reduces heat loss
A battery of e.m.f 3.0V is connected across a potentiometer wire AB of length 10\(\Omega m^{-1}\) as illustrated in the diagram above. If the jockey J makes contact at the 30cm mark, determine the resistance of length AJ and voltage across AJ.
- A. 3.0\(\Omega\); 0.9V
- B. 3.0\(\Omega\); 3.0V
- C. 3.3\(\Omega\); 0.3V
- D. 3.3\(\Omega\); 9.0V
A lamp rated 100W, 240V is lit for 5hours. Calculate the cost of lighting the lamp if 1kWh of electrical energy cost N5.
- A. N2.50
- B. N3.20
- C. N6.50
- D. N9.60
A transformer connected to a 240\(V_{r.m.s}\) has 3000 turns in its primary coil and 500 turns in its secondary coil. Calculate the output voltage.
- A. 4000V
- B. 400V
- C. 40V
- D. 4V
The diagrams above illustrate electrical connections to the element of an electric pressing iron.In which of the connections is the fuse correctly fixed?
- A. I
- B. II
- C. III
- D. IV
Which of the following statements is/ are correct?
I. Gravitational potential due to a mass at a point a distance r away is proportional to \(r^{2}\)
II. Gravitational field strength is a vector quantity
III. Gravitational intensity is proportional to the weight of a unit mass.
- A. I, II and III
- B. III only
- C. II only
- D. I only
A circuit is set up as shown in the diagram above. When the key is closed, the ammeter reading will be
- A. 6A
- B. 4A
- C. 2A
- D. 1A
Which of the following objects is not a conductor of electricity?
- A. The Earth
- B. Human body
- C. Iron rod
- D. Dry wood
The force per unit charge experienced at a point in a field is the
- A. gravitational field strength
- B. electric potential
- C. electric field intensity
- D. magnetic field strength
Two bar magnets are placed near each other. Which of the following diagrams correctly illustrates the magnetic field pattern formed by the pair?
- A. I
- B. II
- C. III
- D. IV
The inverse of the time required for a wave to complete one full cycle is called
- A. wavelength
- B. period
- C. frequency
- D. amplitude
A converging lens of focal length 10cm forms an erect image three times the size of the real object. Calculate the distance between the image and the object.
- A. 6.6cm
- B. 11.1cm
- C. 13.3cm
- D. 20.0cm
Two plane mirrors are inclined at an angle 20° to each other. Determine the number of images formed when an object is placed between them.
- A. 17
- B. 18
- C. 19
- D. 20
The diagram above illustrates a wave setup between two fixed ends 4.0m apart. If the speed of the wave is 1.0\(ms^{-1}\), its wavelength and frequency respectively are
- A. 1m; 0.25Hz
- B. 2m; 0.25Hz
- C. 2m; 0.50Hz
- D. 4m; 0.50Hz
A ray of light incident at an angle \(\theta\) in a rectangular prism grazes the surface of the prism on emerging from the prism. Determine the value of the angle. [Absolute refractive index of the material of the prism is 1.5]
- A. 41.8°
- B. 48.2°
- C. 60.8°
- D. 90.0°
Plane waves through a narrow gap emerge as circular waves. This phenomenon is known as
- A. interference
- B. dispersion
- C. refraction
- D. diffraction
Consider the wave equation: \(y = 10sin(x – 50t)\), What does the number 10 represent?
- A. Acceleration
- B. Speed
- C. Amplitude
- D. Wavelength
Which of the following statements about the 3rd overtone of a vibrating air column of an open pipe is correct? It has
- A. 4 nodes
- B. 5 nodes
- C. 3 antinodes
- D. 4 antinodes
A rainbow is formed when sunlight is incident on water droplets suspended in the air due to
- A. interference
- B. refraction
- C. dispersion
- D. diffraction
The diagram above illustrates two waves of equal amplitudes A and frequencies approaching each other. When the two waves meet at a point I midway between them, the vertical displacement of the resulting wave will be
- A. 0
- B. \(\frac{A}{2}\)
- C. \(\frac{A}{4}\)
- D. \(2A\)