A motor of a corn mill machine operates on electrical energy of 1.44×10⁵J. If one-quarter of the energy is wasted on sound and heat, determine the efficiency of the machine.

• A. 25%
• B. 36%
• C. 64%
• D. 75%

The wavelength of the first overtone of a note in a closed pipe of length 33 cm is?

• A) 33 cm
• B) 44 cm
• C) 22 cm
• D) 17 cm

According to Newton's law of cooling, the heat energy lost per unit area of a body depends on the

I. Surface area

II. Nature of the surface

III. Temperature of the surface

IV. Excess temperature over the surroundings

• A. I and II only
• B. II and IV only
• C. I,II and III
• D. I, II and IV

(a) The diagram below illustrates a projectile motion. Identify each of the physical quantities labeled P, β, H and R.

(b) Write an equation to show the relationship between P, g and Rmax’ where g is the acceleration due to gravity and Rmax is maximum R.

Rainbow formation is as a result of the combination of which of the following phenomena?

(i) Reflection

(ii) Dispersion

(iii) Total internal reflection

(iv) Refraction

• A. (ii) and (iv) only
• B. (i), (iii) and (iv) only
• C. (ii), (iii) and (iv) only
• D. (i), (ii) and (iv) only

Radio waves belong to the class of wave whose velocity is about

• A. 34m/s
• B. 3 ×10⁶m/s
• C. 3 ×10⁸m/s
• D. 3 × 10^-8m/s

In a semi conductor junction diode, as the depletion or barrier layer is forward-biased, the layer

• A. widens
• B. narrows
• C. remains constant
• D. widens then narrows

Which of the following are correct of plane- polarized light? I. Plane polarization of light is the formation of hydrogen bubbles on the particles of light. II. Plane polarization of light is the splitting of light into its spectral components III. Plane-polarized light vibrates in one plane only. IV. Polarization is characteristic of transverse waves.

• A. I and II only
• B. I and IV only
• C. II and III only
• D. III and IV only

The fundamental property of a propagating wave which depends only on the source and not the medium of propagation is the?

• A) wavelength
• B) harmonies
• C) frequency
• D) velocity

A particle starts from rest and moves with a constant acceleration of 0.5 ms^-2? Calculate the time taken by the particle to cover a distance of 25m.

• A. 25s
• B. 7.1s
• C. 10.0s
• D. 50.0s