JAMB Physics 1987 past questions

M1 M2 Fig. 1 Figure 1 above shows two connected bodies of masses m1 and m2 in equilibrium under gravity. The tension in the upper string is

An elevator of mass 4800kg is supported by a cable which can safely withstand a maximum tension of 60 000N. the maximum upward acceleration the elevator can have is

Fig. 2. A 50.0kg block is dropped on a string from a point 10m above (Fig. 2). If the force constant of the spring is 4.0 x 104 Nm-1, find the maximum compression of the spring.

The coefficient os static friction between a 40kg crate and a concrete surface is 0.25. Find the magnitude of the minimum force needed to keep the crate stationary on the concrete base inclined at 450 to the horizontal.[g = 10ms-2]

If a beaker is filled with water, it is observed that the surface of the water is not horizontal at the glass-water interface. This behaviour is due to

The mechanical advantage (MA) of an inclined plane depends on

The distance between the fixed points of centigrade thermometer is 20cm. What is the temperature when the mercury level is 4.5cm above the lower mark?

The length of a side of a metallic cube at 200C is 5.0cm. Given that the linear expansivity of the metal is 4.0 x 10-5 k-1 Find the volume of the cube at 1200C.

As a result of air at the top of a barometer, the height of the mercury column is 73.5cm when it should be 75.0cm; the volume of the space above the mercury is 8.0 cm3 Calculate the correct barometric height when the barometer reads 74.0cm and the volume of the space above the mercury is 6.0 cm3.

Hot water is added to three times its mass of water at 100C and the resulting temperature is 200C. What is the initial temperature of the hot water?

22,000J of heat is required to raise the temperature of 1.5kg of paraffin from 200C. Calculate the specific heat capacity of paraffin.

Calculate the amount of heat required to convert 2kg of ice at –20C to water at 0 0C. (Specific heat capacity of ice = 2090J kg-1 0C-1, specific latent heat of fusion = 333kJ kg-1).

In which of the following are the substances arranged in descending order of their thermal conductivities?

The vacuum in the Thermos flask helps to reduce heat transfer by

Which of the following phenomena explains the fact that a house whose roof is coated with white [PAGE 26] paint will be cooler in the hot season than one coated with black paint?

Which of the following instruments has a pure tone?

When the length I of a piece of wire under constant tension is varied, the relationship of the frequency of vibration f with l is

If an object is placed in front of two mirrors inclined at 900, how many images will be formed?

An object 3.0cm high is placed 60.0cm from a converging lens whose focal length is 20.0cm. Calculate the size of the image formed.

Four lenses are being considered for use as a microscope objective. Which of the following focal lengths is most suitable?

If the angle of declination in a place is 100E, calculate the true geographic bearing if the compass reads N400E.

Two capacitances of 6uF and 8 uF are connected in series. What additional capacitance must be connected in series with this combination to give a total of 3 uF?

P - Fig. 5 In Fig. 5 above, M and N are insulated metal spheres in contact. A negatively charged ebonite rod P is brought near M. when M and N are separated and the rod is taken away, which of the following statements is CORRECT?

When a transformer has more secondary windings than primary winding, it

The direction of the magnetic field at a point in the vicinity of a bar magnet is

When two parallel wires carry currents in opposite directions, the force on either wire is

What type of reaction is represented by the following scheme? 1X + 2 1Y 3Z + 1 0n + energy

Which of the following statements is TRUE of photoelectric effect?

Isotopes are nuclei which have