- The figure below shows a solid sphere with its centre of gravity marked with a dot. The sphere is rolled on a horizontal ground and...(Solved)
The figure below shows a solid sphere with its centre of gravity marked with a dot. The sphere is rolled on a horizontal ground and comes to rest after Some time.Sketch the sphere and mark with a dot the most likely position of the c.o.g after it comes to rest.
Date posted: September 11, 2019. Answers (1)
- The figure below shows water level in limb Q of a glass tube. Indicate the corresponding water levels in limb N, O and P.Explain your...(Solved)
The figure below shows water level in limb Q of a glass tube. Indicate the corresponding water levels in limb N, O and P.Explain your answer.
Date posted: September 11, 2019. Answers (1)
- The figure below shows two identical burning splints. Placed on wood and metal blocks respectively it was observed that when the flame reached the edge...(Solved)
The figure below shows two identical burning splints. Placed on wood and metal blocks respectively it was observed that when the flame reached the edge of the metal block the splint was extinguished while the other on the wooden block continued to burn. Explain this observation.
Date posted: September 11, 2019. Answers (1)
- When washing clothes, it is easier to remove the dirt using some warm water containing soap than cold water. Explain this observation.(Solved)
When washing clothes, it is easier to remove the dirt using some warm water containing soap than cold water. Explain this observation.
Date posted: September 11, 2019. Answers (1)
- The figure below shows the inner parts of a three-pin plug.(Solved)
The figure below shows the inner parts of a three-pin plug.
(i) Identify the pins A and B.
(ii) State the reason why the pin B is normally longer than the other two pins A and C.
Date posted: September 10, 2019. Answers (1)
- State how an increase in thickness affects electrical resistance of a conductor.(Solved)
State how an increase in thickness affects electrical resistance of a conductor.
Date posted: September 10, 2019. Answers (1)
- The figure below shows part of a circuit containing three capacitors.(Solved)
The figure below shows part of a circuit containing three capacitors.
(i) Calculate the effective capacitance between A and B.
(ii) Given that the potential difference (p.d.) across AB is 10V, what is the total charge flowing through the circuit?
Date posted: September 10, 2019. Answers (1)
- State how ‘Hysteresis loss’ can be reduced.(Solved)
State how ‘Hysteresis loss’ can be reduced.
Date posted: September 10, 2019. Answers (1)
- The figure below shows a 12V, 24W lamp operated by a step-down transformer that is connected to a 240V mains supply.(Solved)
The figure below shows a 12V, 24W lamp operated by a step-down transformer that is connected to a 240V mains supply.
(i) Explain what is meant by the term ‗laminated core’ and state its significance in a transformer.
(ii) Calculate the efficiency of the transformer if the current through the primary coil is 0.12 A.
Date posted: September 10, 2019. Answers (1)
- An electric filament bulb is rated 24V, 0.5A.
Calculate:
(i) The power of the bulb.
(ii) The energy dissipated by the bulb in 80 minutes.(Solved)
An electric filament bulb is rated 24V, 0.5A.
Calculate:
(i) The power of the bulb.
(ii) The energy dissipated by the bulb in 80 minutes.
Date posted: September 10, 2019. Answers (1)
- Plane water wave fronts are incident onto reflector SR as shown in the figure below. Show on the diagram the nature and direction of the...(Solved)
Plane water wave fronts are incident onto reflector SR as shown in the figure below. Show on the diagram the nature and direction of the reflected wave fronts.
Date posted: September 10, 2019. Answers (1)
- The graph in the figure below shows the displacement of a pendulum bob from its rest position as it varies with time.(Solved)
The graph in the figure below shows the displacement of a pendulum bob from its rest position as it varies with time.
(i) Determine the amplitude of the oscillation.
(ii) What is the time for one complete oscillation?
(iii) On the same graph, draw a sketch graph which represents a pendulum swinging with half the amplitude and twice the frequency.
Date posted: September 10, 2019. Answers (1)
- The figure below shows an experimental set up consisting of a mounted convex lens L, cardboard screen with cross-wires at the centre, a plane mirror,...(Solved)
The figure below shows an experimental set up consisting of a mounted convex lens L, cardboard screen with cross-wires at the centre, a plane mirror, a metre rule and a candle.
Describe how the set-up may be used to determine the focal length, f, of the lens.
Date posted: September 10, 2019. Answers (1)
- The figure shows a ray of light incident on a glass-air interface.(Solved)
The figure shows a ray of light incident on a glass-air interface.
(i) Show on the diagram the critical angle, c.
(ii) Given that the refractive index of the glass is ang, and that the critical angle c = 42º, determine the value of is ang.
Date posted: September 10, 2019. Answers (1)
- The figure shown below illustrates crests of circular water wave-fronts radiating from a point source O in a pond.(Solved)
The figure shown below illustrates crests of circular water wave-fronts radiating from a point source O in a pond.
State how the depth of the pond at A compares with that at B.
Date posted: September 10, 2019. Answers (1)
- State one example of a transverse-progressive wave.(Solved)
State one example of a transverse-progressive wave.
Date posted: September 10, 2019. Answers (1)
- The figure below shows a wire carrying current whose direction is out of the paper. The wire is placed in a magnetic field.(Solved)
The figure below shows a wire carrying current whose direction is out of the paper. The wire is placed in a magnetic field.
(a) Indicate on the figure the direction of the force F, acting on the wire.
(b) State what would be observed on the wire if the direction of the current is reversed (i.e. into the paper).
Date posted: September 10, 2019. Answers (1)
- State one application of soft iron in magnetism.(Solved)
State one application of soft iron in magnetism.
Date posted: September 10, 2019. Answers (1)
- It is observed that when a rod A is brought near the cap of a negatively charged electroscope, the divergence of the leaf decreases. State...(Solved)
It is observed that when a rod A is brought near the cap of a negatively charged electroscope, the divergence of the leaf decreases. State two deductions that can be made about rod A from this observation.
Date posted: September 10, 2019. Answers (1)
- A mass of 400g is rotated by a string at a constant speed V in a vertical circle of radius 100cm. The minimum tension in...(Solved)
A mass of 400g is rotated by a string at a constant speed V in a vertical circle of radius 100cm. The minimum tension in the string is 7.2 N which is experienced at point T.
(i) Determine the velocity V of the mass at point T.
(ii) Determine the maximum tension in the string.
Date posted: September 10, 2019. Answers (1)