The control grids in a Cathode Ray Oscilloscope (CRO) is used to control the brightness of the beam on the screen. How is this achieved? (Answered) State two differences between the cathode ray tube (CRT) of a T.V and the cathode ray oscilloscope (CRO). (Answered) Figure 3 shows the main features of a cathode ray tube (CRT) of a cathode ray oscilloscope (CRO).
(i) Describe how the electrons are produced in the tube.
(ii) State and explain the function of the grid.
(iii) State what would be observed on the screen if an a.c voltage is connected across the y-plates.
(iv) State how the deflection system of a television differs from that of a CRO.
(Answered) Figure 6 shows a tube for investigating the properties of a beam of electrons. Use the information in the figure to answer question 8. What property of the beam of electrons shows that the electrons are travelling at a very high speed? (Answered) (a) Figure 14 shows the features of a cathode ray tube.
(i) Name the parts labeled A and B.
(ii) Explain how the electrons are produced in the tube.
(iii) State two functions of the anodes.
(iv) At what part of the cathode ray tube would the time be connected?
(v) Why is a vacuum created in the tube? (Answered) Figure 14 (a) is a diagram of a cathode ray tube. M and N are parallel vertical plates
(a) When switch S is open, a spot is seen at the centre of the screen as shown in figure 14(b).
(i) State what happens to the sport when S is closed.
(ii) State what would happen to the spot if the potential difference across MN is increased.
(iii) State what would be seen on the screen if the battery is replace (Answered) State two differences between cathode rays and electromagnetic radiations. (Answered) Explain how electrons are produced in the Cathode ray tube. (Answered) The current of electrons hitting the screen of a cathode ray oscilloscope is 2.0 X #10^-4#A. Determine the number of electrons that strike the screen each second. (Take charge of an electron as 1.6 X#10^-19#C). (Answered) State and explain the function of the Grid in the cathode ray tube. (Answered) State Newton’s first law of motion. (Answered) A trolley is moving at constant speed in friction compensated track. Some plasticine is dropped on the trolley and sticks on it. State with a reason what is observed about the motion of the trolley. (Answered) A gun is fired vertically upwards from the top of an open truck moving horizontally at a uniform velocity of #50 ms^-1#. The bullet achieves a maximum height of 45m.
(i) State with reason whether or not the bullet will land on the truck.
(ii) Calculate the distance covered by the truck just before the bullet reaches the level from
which it was fired. (Use g=10 #ms^-2#). (Answered) An industrial trolley of mass 20kg carrying a mass of 50kg is acted on by a constant force. The trolley moves along a horizontal smooth surface with an acceleration of 0.5 #ms^-2#. Determine the acceleration of the trolley after the mass falls off. (Answered) Two identical spherical steel balls are released from the top of two tall jars containing liquids L1 and L2 respectively. Figure 3 shows the velocity – time graph of the motion of the balls.
Explain the nature of the curves and state why they are different (Answered) A train of mass 200 tonnes starts from rest and accelerates uniformly at 0.5 #ms^-2#.
Determine its momentum after moving 100m (Answered) A high jumper usually lands on thick soft mattress. Explain how the mattress helps in reducing the force of impact. (Answered) State one of the Newton’s law of motion (Answered) A body resting on a horizontal surface is given an initial velocity V so that it slides on the
surface for some distance before coming to a stop. Table 1 shows the distance d moved by the body of various values of V.
Given that #V^2# = 20μd where μ is a constant for the surface, plot an appropriate graph and use it to determine μ. (Answered) A resultant force F acts on a body of mass m causing an acceleration #a1# on the body. When the same force acts on a body of mass 2m, it causes an acceleration #a_2#. Express #a_2# in terms of #a_1# (Answered) A trolley is moving at a uniform speed along a track. A piece of plasticine is dropped on the trolley and sticks on it. Explain why the trolley slows down. (Answered) A footballer kicks a ball of mass 0.6 kg initially at rest using a force of 720N. if the
foot was in contact with the ball for 0.1 seconds, what was the takeoff speed of the ball? (Answered) State newton’s first law of motion. (Answered) A car of mass 800kg starts from rest and accelerates at 1.2 #ms^-2#.
Determine its momentum after it has moved 400m from the starting point (Answered) A cart of mass 30kg is pushed along a horizontal path by a horizontal force of 8N and moves with a constant velocity. The force is then increased to 14N.
Determine:
(a) The resistance to the motion of the cart
(b) The acceleration of th cart. (Answered) Figure 5 is a graph of net force on a body against its velocity as it falls through a liquid.
Determine the terminal velocity of the body (Answered) Figure 12 shows a lorry towing a trailer using a rope.
The lorry exerts a force N on the trailer and the trailer exerts an equal but opposite force M on the lorry. The frictional force between the trailer and the road is F.
Explain how the forces N, M and F enable the trailer to move. (Answered) Figure 13 shows a frictionless trolley of mass 2kg moving with uniform velocity
towards a wall. At the front of the trolley is a spring whose spring constant is 25 Nm-1. The
trolley comes to rest momentarily after compressing the spring by 3cm and the rebounds from the wall.
(i) Determine:
(I) The force exerted on the wall by the spring.
(II) The maximum acceleration of the as it rebounds from the (Answered) A student pulls a block of the wood along a horizontal surface by applying a constant force. State the reason why the block moves at a constant velocity. (Answered) A parachute falling through the air attains terminal velocity after a short time. State the
the reason why it attains terminal velocity (Answered)
