A 10\(\mu\)C charge moves with a velocity of 1.0 x 105 ms-1 at right angle to a uniform magnetic field of flux density 5.0 x 10-4T. Calculate the force on the charge
- A. 5.0 x 10-5N
- B. 5.0 x 10-4N
- C. 5.0 x 105N
- D. 5.0 x 106N
In storing magnets, keepers are used to
- A. reduced self-demagnetization
- B. cancel the effect of the earth's magnetic field
- C. protect the magnet from stray electric field
- D. increase the strangth of the magnets
Two magnets are used to magnetize a soft iron bar PQ as illustrated in the diagram given. The correct polarity at P and Q respectively
- A. S and N
- B. N and N
- C. S and S
- D. N and S
Which of the following factors does not affect the e.m.f of a primary cell? Its
- A. size
- B. internal resistance
- C. operating temperature
- D. duration of usage
Two different materials, rubbed against each other acquired opposite charges when separated. This is an example of charging by
- A. induction
- B. friction
- C. conduction
- D. convection
Two different materials, rubbed against each other acquired opposite charges when separated. This is an example of charging by
- A. induction
- B. friction
- C. conduction
- D. convection
The p.d across a parallel-plate capacitor is 103V. If the distance between the two plates is 10cm. Calculate the magnitude of the electric field strength between the plates.
- A. 1.0 x 104Vm-1
- B. 1.0 x 105Vm-1
- C. 1.5 x 105Vm-1
- D. 2.0 x 105Vm-1
A man and his friend have masses 70kg and 60kg respectively. If they are seated 1.0m apart, calculate the gravitational force of attraction between them. (G = 6.67 x 10-11 Nm2 kg-2)
- A. 1.59 x 10-14 N
- B. 2.80 x 10-7 N
- C. 1.30 x 10-2 N
- D. 6.30 x 1013 N
The electricity meters in houses measure energy unit consumed in
- A. kilowatt-hour
- B. volt
- C. ampere
- D. coulomb
An aluminium cable of diameter 4 x 10-3m and resistivity 3.0 x 10-8\(\omega\)m has a resistance of 21\(\Omega\). Calculate the length of the cable. (\(\pi = 3.14\))
- A. 8.0 x 102m
- B. 8.8 x 103m
- C. 8.0 x 104m
- D. 8.8 x 104m
An astronomical telescope has objectives and eye-piece lenses of focal length 3.5m and 5cm respectively. Determine the magnifying power of the telescope when in normal adjustment
- A. 70.0
- B. 17.5
- C. 7.0
- D. 0.7
The pair of musical instruments that works on the vibration of air in pipes is
- A. piano and the organ
- B. guitar and the flute
- C. trumpet and the violin
- D. flute and the trumpet
The diagram given illustrates the waveform of a note produced by vibrations in an air column of length L. If the speed of sound in air is V, derive an expression for the frequency of the notes
- A. \(\frac{V}{L}\)
- B. \(\frac{5VL}{2}\)
- C. \(\frac{5L}{4V}\)
- D. \(\frac{5V}{4L}\)
Complementary colours are those which
- A. have the same refractive index
- B. have the same wavelength
- C. add-up to produce black light
- D. add-up to produce white light
Total internal reflection. i. is a phenomenon of refraction of light. ii. occurs when light rays travel into a denser medium. iii. occurs when the critical angle is just exceeded. iv. is a phenomenon of reflection of light. Which of the statements above are correct?
- A. i and ii only
- B. i and iii only
- C. i, ii and iii only
- D. i, iii and iv only
The image formed by a concave mirror is real, inverted and magnified, when object is placed
- A. at the focus
- B. at the centre of curvature
- C. beyond the centre of curvature
- D. between the centre of curvature and the focus
X-rays and infrared rays are both electromagnetic. Which common property do the waves have? Both waves
- A. are longitudinal
- B. have same frequency
- C. have the same wavelength
- D. travel at the same speed in a vacuum
The distance between two successive trough of a wave is 0.4m. If the frequency of the source is 825Hz, Calculate the speed of the wave
- A. 165.0 ms-1
- B. 330.0ms-1
- C. 41.5ms-1
- D. 85.0ms-1
Given that v, f and \(\lambda\) are the velocity, frequency and wavelength of a wave respectively. Which of the following equations is correct?
- A. v = f2\(\lambda\)
- B. f = \(\frac{v}{\lambda}\)
- C. f = \(\frac{v}{\lambda^2}\)
- D. \(\lambda = \frac{f}{v^2}\)
A pressurized perfume bottle is left on the window pane of a room. What happens to he gas molecules of the perfume on a sunny day? They
- A. expand
- B. collide less often
- C. move more rapidly
- D. contract
Which of the following statements is correct about the effect of dissolved salt on the freezing point of water?
- A. the freezing point is lowered
- B. the freezing point is increased
- C. there is no change in the freezing point
- D. the change in the freezing point depends on the temperature of the surrounding