Jamb 2002 Physics Past Questions And Answers
The electromagnetic wave that can produce a heating effect on the environment is
- A. x -rays
- B. ultraviolet rays
- C. infrared rays
- D. gamma rays
A current of 0.5 A flowing 3h Deposits 2g of metal during electrolysis. The quantity of the same metal that would be deposited by the currents of 1.5A flowing in 1h is
- A. 2g
- B. 6g
- C. 10g
- D. 18g
an electric cell with nominal voltage E has a resistance of 3Ω connected across it. If the voltage falls to 0.6E, the internal resistance of the cell is
- A. 1Ω
- B. 2Ω
- C. 3Ω
- D. 4Ω
A transistor is used in the amplification of signals because it
- A. controls the flow of current
- B. consumes a lot of power
- C. allows doping
- D. contains electron and hole carriers
Two force each of 10N acts on a body, one towards the north and the other towards the east. The magnitude and the direction of the resultant force are
- A. 20N, 45°E
- B. 20N, 45°W
- C. 10√2N, 45°W
- D. 10√2N, 45°E
Pure silicon can be converted to a p-type by adding a controlled amount of
- A. trivalent atoms
- B. tetravalent atoms
- C. pentavalent atoms
- D. hexavalent atoms
A wheel and axle is used to raise a load of 500 N by the application of an effort of 250 N. If the radii of the wheel and the axle are 0.4 cm and 0.1 cm respectively, the efficiency of the machine is
- A. 20 %
- B. 40 %
- C. 50 %
- D. 60 %
From the generating station to each substation power is transmitted at a very high voltage so as to reduce
- A. hysteresis loss
- B. eddy current loss
- C. magnetic flux leakage
- D. heating in the cells
Vibration in a stretched spring cannot be polarized because they are
- A. stationary waves
- B. transverse waves
- C. longitudinal waves
- D. mechanical waves
Which of the following statements is true of the properties of a moving coil galvanometer?
- A. THe coil has a small area
- B. There are strong hair springs to gives a large control panlel
- C. There is a strong permanent magnet to give high magnetic flux
- D. it has a small number of turns of coil