Physics Past Questions And Answers
What quantity of heat is required to convert 20 g of ice at 0 ºC to water at the same temperature? (Specific latent heat of ice = 336 Jg-1)
- A. 7.06 x 103J
- B. 5.38 x 103J
- C. 6.72 x 103J
- D. 1.35 x 103J
A concave mirror of radius of curvature 40 cm forms a real image twice as large as the object. the object distance is
- A. 10 cm
- B. 30 cm
- C. 40 cm
- D. 60 cm
a. State one difference between an intrinsic and an extrinsic semiconductor.
b. Draw a circuit diagram to illustrate full wave smoothing rectification.
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A device that converts mechanical energy into electrical energy is
- A. a dynamo
- B. an electric motor
- C. an induction coil
- D. a transformer
At a birthday party, the celebrant pops a corked fruit wine. If the cork shoots out of the bottle at an angle of 40o to the horizontal and travels a horizontal distance of 4.50m in 1.25s. Calculate the initial speed of the cork.
- A. 4.2ms-1
- B. 4.7ms-1
- C. 5.6ms-1
- D. 7.1ms-1
The invisible part of the spectrum of a white light consists of the following colors
- A. Red, orange and yellow only
- B. Infra-red, ultraviolet and blue only
- C. Indigo and green only
- D. Ultra violet and infra-red only
A platinum resistance thermometer wire has a resistance of 5 ohms at 0oC and 5.5 ohms at 100oC. Calculate the temperature of the wire when the resistance is 5.2 ohms
- A. 80oC
- B. 60oC
- C. 40oC
- D. 10oC
Steel bars, each of length 3.0 m at 28°C, are to be used for constructing a rail line. If the linear expansivity of steel is 1.0 x 10-5°C, what is the safety gap that must be left between successive bars if the highest temperature expected is 40oC?
- A. 1.2 x 10-1cm
- B. 8.4 x 10-2cm
- C. 7.2 x10-2cm
- D. 3.6 x 10-2cm
Formation of hydrogen bubbles at the copper plate of a primary cell is called?
- A. polarization.
- B. back e.m.f.
- C. electrolysis.
- D. local action.
A particle is dropped from a vertical height h and falls freely for a time t. With the aid of a sketch, explain how h varies with
(a) t;
(b) t\(^2\).
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