Second Term Examination
Class : SSS 2
Subject : Physics
Name : __________________________________
Section A : Objective Questions
Instruction : Read the question carefully and pick from the options lettered a – d.
1. The amount of heat required to raise the temperature of a unit mass of a gas through one degree at constant volume (a) Heat capacity (b) Specific Heat capacity (c) Latent Heat (d) Vaporization
2. The heat capacity depends on whether the heat is added at constant ____________ or constant ____________. (a) Volume, temperature (b) Pressure, volume (c) Pressure, Temperature (d) Temperature, Vapours pressure
3. How much is required to change 10kg of an object 20°c to 70°c? Specific heat capacity of the object is 200j/kg/k. (a) 1 x 10 5 J (b) 1 x 10 4 J (c) 40j (d) 1000j
4. How much heat is generated when an electrical coil rated 200W is used to heat a given mass of water for 1hour. (a) 600kj (b) 720kj (c) 1200kj (d) 1500kj
5. An electric heater rated 12V is used to heat 450g of water when a current of 5A was passed through it. What is the increase in temperature after 30minutes. (Specific Heat Capacity of Water = 4200J/kg/k). (a) 95k (b) 80k (c) 65k (d) 57k
6. Calculate the temperature found when 10kg of water at 100°c mixed with 20kg of water at 40°c. (a) 6°c (b) 16°c (c) 600°c. (d) 0.6°c
7. 0.5kg of water at 10°c is completely converted to ice by extracting 18800J of heat from it. If the specific heat capacity of water is 4200J/kg/k, calculate the specific latent heat of fusion of ice. (a) 9.0KJ/kg. (b) 84.0KJ/kg. (c) 168.0KJ/kg (d) 334KJ/kg
8. The unit of latent heat is ______________. (a) Joule/Kelvin (b) Joule/ kg-¹ (c) Joule/kg (d) Joule
9. Calorimeter is a device for measuring (a) Specific heat capacity (b) Specific gravity (c) Temperature (d) Latent heat
10. The amount of energy required to change liquid to gas and vice versa without à changé in temperature is termed (a) Latent heat of fusion (b) Latent heat of vaporization (c) Heat capacity (d) Specific Heat capacity
11. Calculate the heat energy required to vaporize 50g of water initially at 80°c, if the specific heat capacity of water is 4.2Jg-¹K. (specific latent heat of vaporization of water is 2260Jg-¹) (a) 533000J (b) 230000J (c) 117200J (d) 113000J
12. The temperature of a piece of metal of mass 9g is raised from 10°c to 110°c when it absorbs 108J of heat energy. Determine the specific heat capacity f the metal in JKg-¹K-¹. (a) 1.2 (b) 12.0 (c) 120.0 (d) 1200.0
13. Calculate the heat energy required to change 0.1kg of ice at 0°c to water boiling at 100°c. (Specific heat capacity of water = 4200Jkg-¹K-¹) (Specific latent heat of fusion of ice = 336,000Jkg-¹) (a) 75600J (b) 336,000J (c) 340,200J (d) 378,000J
14. When you hang a shirt or jeans on a rope to dry it out, it dries faster even if there is sun, this is due to (a) Boiling perfume (b) Evaporation of liquid (c) Melting of the liquid (d) Condensation of the liquid
15. The thermometer whose reading is indicated by a change in color of its thermometric property is the ___________. (a) bí-metallic strip thermometer (b) thermocouple (c) platinum resistance thermometer (d) optical pyrometer
16. At 4°c, the volume of a fi$e$ MASS of water is ____________. (a) constant (b) minimum (c) maximum (d) zero
17. Water in an pen container boils at a lower temperature when heated at the top of a mountain than at sea-level because at the top of a mountain the (a) relative humidity is higher than at sea-level (b) rays of the sun adds more heat to the water (c) temperature is lower than that at sea-level (d) pressure is lower than that at sea-level
18. All the heat generated by a current of 2A passing through a resistor of 6Ω for 2.5s is used to evaporate 5g of a liquid at its boiling point. What is the specific latent heat of the liquid? (a) 60Jg-¹ (b) 120Jg-¹ (c) 300Jg-¹ (d) 150Jg-¹
19. Which of the following will affect the saturation vapour Pressure of a liquid? (a) Temperature of the liquid (b) Humidity of air (c) Volume of vapour (d) Volume of the liquid
20. The temperature at which the water vapour present in the air is just sufficient to saturate it is called the _______________. (a) ice point (b) Boiling point (c) steam point (d) dew point (e) saturation point
21. Which of the following instrument may be used to measure the relative humidity? (a) Hydrometer (b) Barometer (c) Manometer (d) Hypsometer (e) Hygrometer
22. Given that v, f and λ are the velocity, frequency and wavelength of a wave respectively. Which of the following equations is correct? (a) V = f²λ (b) f = v/ λ (c) f = v/ λ² (d) λ = f/v²
23. The change of the direction of a wavefront as a result of a change in the velocity of the wave in another medium is called _____________. (a) refraction (b) reflection (c) diffraction (d) polarization
24. What is the saturated vapour Pressure at STP, if the partial pressure of water vapour at 27°C is 18mmHg and the saturated vapour pressure of the atmosphere at the same temperature is 24 mmHg, the relative humidity at this temperature is ___________? (a) 25% (b) 33% (c) 75% (d) 82%
25. Which of the following waves are longitudinal waves? I. Ripples on the surface of water II. Waves produced by a turning fork vibrating in air III. Light waves IV. Waves produced by a flute. (a) I and II only (b) I and III only (c) II and III only (d) II and IV only (e) III and IV only
26. A thermometer has its stem marked in millimeter instead of degree Celsius. The lower fixed point is 30mm and the upper limit is 180mm. Calculate the temperature in degree Celsius when the thermometer reads 45mm. (a) 67.5°C (b) 30.0°C (c) 25.0°C (d) 15.0°C
27. Which of the following statements is/ are not correct? (a) Evaporation takes place only at the surface of the liquid (b) Boiling takes place throughout the volume of the liquid (c) Evaporation takes place at all temperature (d) Boiling takes place at a particular temperature for a liquid at a fixed external pressure.
28. The distance between the node and anti-node for a transverse wave is equal to (a) the wavelength (b) thrice the wavelength (c) one-half of the wavelength (d) one – quarter of the wavelength
29. In a wave the maximum displacement of particles from their Equilibrium positions is called __________. (a) frequency (b) amplitude (c) period (d) wavelength
30. Which of the following is not a property of longitudinal waves? (a) compression (b) refraction (c) polarization (d) diffraction
31. A simple pendulum makes 50 oscillations in one minute. What is its period of oscillation? (a) 0.02s (b) 0.20s (c) 1.20s (d) 0.83s
32. The mirror used in car driving is __________. (a) Plane (b) Concave (c) Convex (d) Parabola
33. An object is placed in front of a concave mirror of focal length 0.10cm and gives a real image three times the size of the object. Where is the object placed? (a) 1.33m (b) 13.3m (c) 0.133m (d) 133m
34. The distance of an object from a curved concave mirror is 30 and the image is formed 60cm away from the mirror. What is the magnification of the mirror
35. A concave mirror of radius of curvature 30cm produces an image 3 times the size of the object. The distance of the object from the mirror is? (a) 7.5cm (b) 11.3cm (c) 15.0cm (d) 20cm
36. 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) 165.0ms-¹ (b) 330ms-¹ (c) 41.5ms-¹ (d) 85.0ms-¹
37. The image formed by a concave mirror is real, inverted and magnified, when the 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
38. Which of the following properties is not exhibited by sound wave? (a) Diffraction (b) Polarization (c) Interference (d) Reflection
39. During thunderstorm, the sound is heard over a long time. This phenomenon is referred to as __________. (a) diffraction of sound (b) refraction of sound (c) superposition (d) reveraberation
40. The fundamental property of a propagating wave which depends only on the source and not the medium of propagation is the ______________________. (a) wavelength (b) harmonics (c) frequency (d) velocity
41. In a ripple tank experiment, a vibrating plate is used to generate ripples in the water. If the distance between two successive through is 3.5cm and the wave travels a distance of 31.5cm in 1.5s, calculate the frequency of the vibratory. (a) 3.0Hz (b) 6.0Hz (c) 12.0Hz (d) 27.0Hz (e) 73.5Hz
42. If the pressure of the vapour on top of an enclosed see liquid is equal to the atmospheric pressure, what will be the temperature of the liquid enclosed? (a) room temperature (b) boiling point (c) freezing point (d) standard temperature
43. A heating coil rated 1000W is uses to boil off completely 2kg of boiling water. The time required to boil the water is? (Specific latent heat of Vaporization of water = 2.3 x 106 Jkg-¹) (a) 1.15 x 10 4 s (b) 1.15 x 10³s (c) 4.6 x 104s (d) 4.6 x 10s
Section B : Theory
Instruction : Answer four questions from this section. Question One is compulsory.
1ai. Distinguish between heat and temperature.
aii. State two physical properties of substances which may be used to measure temperature.
aiii. State two reasons why mercury is preferred to alcohol as a thermometruc liquid.
1b. A piece of copper block of mass 24g at 230°C is placed in a copper calorimeter of mass 60g containing 54g of water at 31°C. Assuming heat losses are negligible, calculate the final steady temperature of the mixture. (Specific heat capacity of water = 4200JKg-¹K-¹) (Specific heat capacity of copper = 400JKg-¹K-¹)
1ci. State three properties of waves
cii. Draw a ray diagram showing how a virtual image of an object is formed by a concave mirror.
d. The equation, y = sin(3x – 4t), where y is in millimeters, x is in metre and t is in seconds represents a wave motion. Determine the ;
i. Frequency
ii. Period
iii. Speed of the wave
2ai. Define Specific heat capacity.
aii. What is meant by the statement: The specific heat capacity of copper is 400Jkg-¹K-¹?
b. Water falls through a height of 50m. Determine the temperature rise at the bottom of the fall. (Neglect energy losses. Specific heat capacity of water = 4200Jkg-¹K-¹, g = 10ms-¹)
c. State four difference between boiling and evaporation.
3ai. Distinguish between Dew and fog.
aii. Saturated and unsaturated vapour
b. An immersion heater rate d 400W, 220V is used to heat a liquid of mass 0.5kg. If the temperature of the liquid increases uniformly at the rate of 2.5°C per second, calculate the specific heat capacity of the liquid. (Assume no heat is lost)
c. Define refractive index for waves passing from one medium to another in terms of :
i. Angles
ii. Velocitues
4a. Define Stationary wave
b. If saturated vapour Pressure of air at 20°C is 16.45mmHg at dew point. Determine the relative humidity if the temperature at dew point is 10°C.
c. When the wavelength of wave travellings with a velocity of 360ms-¹ is 60cm. Calculate the period of the wave.
5ai. Define Relative Humidity
aii. State the characteristics of Transverse waves and longitudinal waves and give one example of each.
b. An object is placed 30cm from a concave mirror of focal length 15cm. Find the linear magnification of the image produced.
c. 0.5kg of water at 10°C is completely converted to ice at 0°C by extracting 188000J of heat from it. If the specific heat capacity of water is 4200 Jkg-1K-1, calculate the specific latent heat of fusion
6a. Write three differences between electromagnetic waves and mechanical waves and give two examples of each.
b. The resistance of platinum is 5.684 ohms at the temperature of steam at 760mm mercury and 5.240 ohms at the temperature of melting ice. If the resistance at the temperature of a warm is 5.490 ohms, calculate the liquid temperature.
c. A ray of light experience a minimum deviation when passing symmetrically through an equilateral triangular glass prism. Calculate the angle of incidence of the ray. ( Refractive index of glass = 1.5)