Grade 12 Physics May June 2021 Eng Paper 1

When light of various frequencies is incident on the metal cathode of a photocell,photoelectrons are emitted from the surface of the cathode.The graph below shows the relationship between the maximum kinetic energy (Ek(max))of an emitted photoelectron and the wavelength of the incident light. 10.1 Use the graph to determine the maximum kinetic energy of the … Read more

The diagram below is a simplified representation of an AC generator. The coil isrotated in a clockwise direction in the magnetic field. 9.1 Write down the name of component X. (1) 9.2 Write down the function of component Y. (1) 9.3 Use the relevant principle to explain why an emf is induced in the coil … Read more

Three resistors are connected to a battery with an unknown emf and unknown internalresistance r, as shown below.Ignore the resistance of the connecting wires. 8.1 In the definition of the emf of a battery given below, (a) and (b) representmissing words or phrases.The emf of the battery is the maximum (a) … supplied by a … Read more

Two charged spheres, R and S, are both stationary on a smooth, insulated surfaceinclined at an angle of 25° to the horizontal. Sphere S, of mass 0,01 kg and carrying acharge of –6 x 10-9 C, is connected to a 0,03 m long, light inextensible string attachedto point P at the top of the incline.Sphere … Read more

6.1 State the Doppler effect. (2) 6.2 Use the graph to answer the following questions. 6.2.1 Write down the frequency of the sound emitted by the stationarysource.Give a reason for the answer. (2)6.2.2 In which direction is the car moving relative to the source?Choose from TOWARDS or AWAY.Give a reason for the answer. (2)6.2.3 Calculate … Read more

A demolition ball is used by a crane to break the wall of a building.The demolition ball, of mass 1 250 kg, is lifted by the crane to a point R at a height of5,8 m above its lowest position in 60 s.Ignore air friction. 5.1 Define the term power in words. (2) 5.2 Calculate … Read more

A simple rocket system consists of two parts, A of mass 3m, and B of mass 2m, asshown in the diagram below. B is stacked on top of A. Ignore ALL external forces on the rocket.4.2 Calculate the velocity of B in terms of v immediately after the internalexplosion. (5)The graph below shows the average … Read more

3.1 Name the force acting on the ball while it is in free fall. (1) The velocity-time graph below represents the motion of the ball from the instant it isthrown upwards until it hits the ground. 3.2 Write down the acceleration of the ball at time t = 1,02 s. (2) 3.3 Consider the areas … Read more

An 8-kg block, on a rough horizontal surface, is connected to a 2-kg block by a lightinextensible string passing over a frictionless pulley, as shown below. The 8-kg blockmoves at a constant speed when pulled by a 29,6 N horizontal force to the right.The frictional force acting on the 8-kg block is 10 N. 2.1 … Read more