The diagram shown represents a block-and-tackle pulley system on which an effort of W Newtons supports a load of 120.0N. If the efficiency of the machine is 40, then the value of W is?

• A. 28.0
• B. 48.0N
• C. 233.0N
• D. 50.0N

A zinc has a heat capacity of 40 J/K, what is the mass of the zinc, given that the specific heat of zinc is 380 J/kg k

• A. 0.11kg
• B. 0.12kg
• C. 0.13kg
• D. 0.14kg

The instrument that measures both a.c and d.c is?

• A) a current balance
• B) a moving current ammeter
• C) a moving iron ammeter
• D) an inverter

A device consumes 100 W of power when connected to a 120 V source. Calculate its resistance.

• A. 1.2\(\Omega\)
• B. 12,000 \(\Omega\)
• C. 20.0\(\Omega\)
• D. 144\(\Omega\)

A piece of substance of specific heat capacity 450Jkg\(^{-1}\)k\(^{1}\) falls through a vertical distance of 20m from rest. Calculate the rise in temperature of the substance on hitting the ground when all its energies are converted into heat. [g = 10ms\(^{-2}\)]

• A. \(\frac{2}{9}\)ºC
• B. \(\frac{4}{9}\)ºC
• C. \(\frac{9}{2}\)ºC
• D. \(\frac{9}{4}\)ºC

Each of the following physical quantities is classified as a vector or a scalar quantity. Which of the classifications is correct?

• A. electric potential (Vector)
• B. momentum (scalar)
• C. gravitational field intensity (scalar)
• D. magnetic flux density (vector)

A body is whirled round a circular path at constant speed. Which of the following diagrams correctly indicates the direction of the body's velocity (v) and its acceleration (a)?

• A. I
• B. II
• C. III
• D. IV

The linear expansivity, \(\alpha\), and cubic expansivity, \(\gamma\), of a material are related by the equation?

• A. \(\gamma\)=a
• B. \(\gamma\)=3\(\alpha\)
• C. \(\gamma\)=2a
• D. \(\gamma\)=\(\frac{1}{3} \alpha \)

A ray of light travels obliquely from a less dense medium to a denser medium. Which of the following statements is true about the light?

• A. The wavelength of the light increases in the second medium
• B. The speed of the light increases in the second medium
• C. The light refracts towards the normal
• D. There Is a change in the frequency of the light

A load of mass120kg is raised vertically through a height of 2m in 30s by a machine whose efficiency is 100%. Calculate the power generated by the machine. [g = 10ms^-2]

• A. 60W
• B. 80W
• C. 100W
• D. 120W