NECO SSCE - Physics - 2003

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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Lenz’s law of electromagnetic induction states that

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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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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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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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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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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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The space surrounding a magnet in which the magnetic force is exerted is

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Which of the following properties is NOT exhibited by sound waves?

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J.J. Thomson’s model of the atom was abandoned because

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Young’s modulus of elasticity is the ratio of stress to strain, provided the load does not exceed the

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The S.l unit of magnetic flux density is

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A sheet of white paper viewed through blue glass appears blue because

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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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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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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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The motion of the prongs of a sounding turning fork is

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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

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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.

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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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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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The mode of transference of heat which does not require any material medium is

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Which of the following instruments can be used to measure e.m.f. most accurately.

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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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\(^{226}_{88}Ra\) \(\to\) \(^{222}_{866}Rn\) + X + Energy. The equation above represents a nuclear decay of radium isotope. What is X?

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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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A body that produces its own light is said to be

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Which of the following statements about the concept of solid friction is NOT true?

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Which of the following statements is NOT true?

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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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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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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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Calculate the critical angle for light travelling from water to air. (Refractive index of water = 1.33)

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An evidence of the wave nature of matter is

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Which of the following radiations have the longest wavelength?

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Which of the following scientists postulated that moving particles exhibit wave properties?

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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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The inability of the eye to focus near objects is known as

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For which of the following sets are the units fundamental?

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A short chain is usually attached to the rear side of petro tanker trailing behind it to ensure that the

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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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Evaporation of a liquid produces cooling of the liquid because the

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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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The area under the curve of a velocity time graph represents

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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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