An astronomical telescope having an objective of focal length 100cm and an eyepiece of focal length 10cm is used in normal adjustment, calculate the separation of the lenses

• A. 0.10m
• B. 0.90cm
• C. 1.10m
• D. 1.80m

(a) What is a vector quantity?

(b) Three vectors 3 ms\(^{-1}\) N 45° W, 12 ms\(^{-1}\)W and 5 ms\(^{-1}\)S act at a point.

(i) Sketch a vector diagram to illustrate the given information.

(ii) Calculate the resultant of the vectors.

(c) In a laboratory experiment to determine the force constant of a spiral spring, the mass or, the spring was varied and the corresponding extensions were measured and recorded as shown in the table below.

(i) Copy and complete the table. (Take g = 10 ms\(^{-2}\))

(ii) Plot a graph with weight, W, on the vertical axis and extension, e, on the horizontal axis.

(iii) Using the graph, determine the force constant of the spring.

(iv) Determine the natural length of the spring if its length was 38.0 cm when loaded with 250 g mass.

Which of the following statements is not correct?

• A. molecules of ice, water and water vapour have equal intermolecular distances
• B. molecules of ice, water and water vapour do not differ in the structure of their molecules
• C. molecules of water vapour attract each other with forces far less than the forces of attraction between water molecules
• D. water is less compressible than water vapour

The length of mercury thread when it is at 0°C, 100°C and at an unknown temperature \(\theta\) is 25mm, 225mm and 175mm respectively. The value of \(\theta\) is

• A. 85.0^oC
• B. 80.0^oC
• C. 75.0^oC
• D. 70.0^oC

A rainbow is formed when sunlight is incident on water droplets suspended in the air due to

• A. interference
• B. refraction
• C. dispersion
• D. diffraction

A capacitor of 20 x 10^-12F and an inductor are joined in series. The value of the inductance that will give the circuit a resonance frequency of 200kHz is

• A. I/16 H
• B. I/8 H
• C. I/64 H
• D. I/32 H

A cell of e.m.f. 1.5V and internal resistance 1.0\(\Omega\) is connected to two resistor of resistance 2.0\(\Omega\) and 3.0\(\Omega\) in series. Calculate the current through the resistors

• A. 0.25A
• B. 0.30A
• C. 0.35A
• D. 0.50A

When 100g of liquids L1 at 78°C was mixed with Xg of liquid L2 at 50°C, the final temperature was 66°C. Given that the specific heat capacity of L2is half that of L1, find x

• A. 50g
• B. 100g
• C. 150g
• D. 200g

An object falls freely from a height of 25m onto the roof a building 5m high. Calculate the velocity with which the object strikes the roof (g=10\(ms^{-2}\)

• A. 17.3\(ms^{-2}\)
• B. 20\(ms^{-2}\)
• C. 24.5\(ms^{-2}\)
• D. 125\(ms^{-2}\)

Which of the following statements about moving particle is correct?

• A. if the resultant force acting on the particle is zero, then it is in dynamic equilibrium
• B. If the resultant force acting on the acting on the particle is greater than zero, then it is moving with a uniform velocity
• C. the rate of change of its momentum with time tales place in a direction opposite to that of its motion
• D. the particle falling freely covers equal distances in equal time interval