FORM FOUR PHYSICS NECTA 2010

i)Which one of the following statements about alpha and beta particles is correct?

1.  They carry the same charge.
2.  Each alpha particle has four times the mass of beta particle.
3. Alpha particles have larger range in air than beta particles.
4. When in motion, they are deflected in opposite directions by a magnetic field.
5. Alpha particles cause ionization while beta particles do not.

Light waves differ from sound waves because:

1.  light is an electromagnetic wave but sound is a mechanical wave
2.  sound waves do not travel in water but light waves do.
3.   the speed of light is independent of the medium it travels but the speed of sound depends on the medium.
4.  interference is obtained with light waves but not with so waves.
5.  the speed of sound waves is greater than that of light waves in the same medium.

(iii)     In a laboratory, the diameter of a piece of wire can accurately measured by:

1. Vernier Calliper
2. Micrometer screw gauge
3. Engineers Calliper
4. Rate meter
5. A thread wound round it once.

(iv)     A basic condition for diffraction of a wave when it passes through an opening is that:

1. the wavelength of the incident wave must be greater than the size of the opening.
2. the amplitude of the wave must be less than the size of the opening.
3. the wavelength ofthewave must be shorter than the corresponding size of the opening.
4. the wavelength of the wave must almost be equal to the size of the opening.
5. the amplitude of the wave must be greater than the opening.

(v)       The specific latent heat offusion of a substance is defined as the energy required to:

1. change a unit mass of the substance from solid to liquid.
2.  change a unit mass of a substance from solid to liquid at constant temperature.
3. change the mass of substance from solid to liquid at constant temperature.
4. cause a unit temperature rise of a substance.
5. cause a unit mass of water to freeze at OOC.

(vi)     For an oscilloscope just to display the wave form of a.c supply which controls should be adjusted?

1. Y-shift then X-time base
2.  X-time base then Y-shift
3.   Y-shift then brightness
4. X-time base the T-gain
5. . Y-gain then focus.

(vii)   A regular rise and fall in loudness of a music player at a distance is called:

1. intensity
2. timbre
3. pitch
4. beats
5. resonance

(viii)Which of the following are non-magnetic metals?

1. Iron and Steel
2.  Aluminium and Zinc
3.  Nickel and Cobalt
4. Nickel and Steel
5.  Iron and Cobalt

(ix)     The temperature of a liquid in a thermos flask remains unaltered for a long time because heat loss by:

1. conduction is minimized.
2. convection and radiation are reduced.
3. radiation and convection are minimized.
4.  conduction and radiation are reduced.
5. all modes of heat transfer are reduced.

(x)       A body is said to be in equilibrium if:

1.  it moves with uniform speed.
2.  the net force acting on the body is zero.
3. the upward forces on the body counter-balance some of the downward forces.
4.  its centre of gravity is low positioned.
5.  its centre of gravity is high.