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Vraag 1 Verslag
How much heat is required to convert 50g of water at 100°C to steam at the same temperature? (Specific latent heat of vaporization of water = 2260 Jg-11)
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Vraag 2 Verslag
Which of the following motions will be produced by a pair of equal, opposite and non-collinear parallel forces acting on a body?
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Vraag 4 Verslag
Lines of force
I. Begin and end on equal and opposite electric charges.
II. are in state of tension which causes them to shorten
III. attract one another.
Which of the statement(s) is/are correct?
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Vraag 6 Verslag
The distance between two successive crests of a water wave is 0.5m. If a particle on the surface of the water wave makes two complete vertical oscillations in 1s, calculate the speed of the wave.
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Vraag 7 Verslag
The mode of transference of heat which does not require any material medium is
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Vraag 8 Verslag
A wire of length 100cm and cross-sectional area 2.0 × 10-3cm2 has a resistance of 0.10 ω. Calculate its electrical conductively.
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Vraag 9 Verslag
Calculate the critical angle for light travelling from water to air. (Refractive index of water = 1.33)
Vraag 10 Verslag
Which of the following scientists postulated that moving particles exhibit wave properties?
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Vraag 11 Verslag
A transformer is required to give 120V from a 240V mains supply. If the primary has 5500 turns, how many turns has the secondary?
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Vraag 12 Verslag
A narrow, uniform glass tube, closed at one end, constains air which is sealed by a thread of mercury. The tube is placed first horizontally and then vertically with the open end at the top. Which of the following statements is correct?
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Vraag 13 Verslag
A body is launched from the earth’s surface, of radius R, so that it just escapes from the gravitational influence of the earth; If the gravitational constant is G and the mass of the earth is M, what is the escape velocity of the boby.
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Vraag 14 Verslag
Calculate the amount of heat generated in an external load of resistance 8Ω if an alternating current of peak value 5 A is passed through it for 100s.
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Vraag 16 Verslag
A ball of mass m moving at velocity u collides with another ball of equal mass at rest. If the two balls move off together after the impact, calculate their common velocity.
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Vraag 17 Verslag
The resistance of a series R-C circuit is 5 ω If the impedance of the circuit is 13 ω calculate the reactance of the capacitor
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Vraag 18 Verslag
A sheet of white paper viewed through blue glass appears blue because
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Vraag 21 Verslag
The volume of a given mass of gas is 40cm3 at 27° C. What is its volume at 90° C if its pressure remains constant?
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Vraag 22 Verslag
Which of the following radiations have the longest wavelength?
Vraag 23 Verslag
Which of the following statements about the concept of solid friction is NOT true?
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Vraag 24 Verslag
Which of the following instruments can be used to measure e.m.f. most accurately.
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Vraag 26 Verslag
Young’s modulus of elasticity is the ratio of stress to strain, provided the load does not exceed the
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Vraag 27 Verslag
Which of the following statement(s) is/are correct about the isotopes of an elements? They have the same
I. chemical properties
II. nucleon number
III proton number
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Vraag 28 Verslag
The space surrounding a magnet in which the magnetic force is exerted is
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Vraag 30 Verslag
A machine has an efficiency of 80%. If the machine is required to overcome a load of 60N with a force of 40N, calculate its velocity ratio.
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Vraag 31 Verslag
Which of the following statement(s) is/are correct?
I. When a liquid expands its density falls
II. When a mercury-in-glass thermometer is placed in a hot liquid, the mercury level first descends and then rises.
III. The apparent expansion of a liquid is greater than its real expansion.
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Vraag 32 Verslag
A platinum-resistance thermometer has a resistance of 4Ω at 0°C and 12Ω at 100°C. Assuming that the resistance changes uniformly with temperature. Calculate the resistance of the thermometer when the temperature is 45°C.
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Vraag 34 Verslag
Two equal capacitances are connected first in series and then in parallel. The ratio of the effective series capacitance to the effective parallel capacitance is
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Vraag 35 Verslag
An object is placed 30 cm in front of a concave mirror of focal length 20cm. Calculate the distance between the object and the image.
Vraag 36 Verslag
\(^{226}_{88}Ra\) \(\to\) \(^{222}_{866}Rn\) + X + Energy. The equation above represents a nuclear decay of radium isotope. What is X?
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Vraag 37 Verslag
A stone is released from a height of 80m above the ground. Calculate its velocity just before it strikes the ground. (g=10ms-2)
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Vraag 38 Verslag
A constant force of 5N acts for 5s on a mass of 5kg initially at rest. Calculate the final momentum of the mass.
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Vraag 41 Verslag
Water in an open 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
Vraag 42 Verslag
In 90 seconds, the mass of a radioactive element reduces to \(\frac{1}{16}\) of its original value. Determine the half- life of the element.
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Vraag 43 Verslag
A short chain is usually attached to the rear side of petro tanker trailing behind it to ensure that the
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