A student investigates the efficiency of a filament lamp. Fig. 4.1 shows the filament lamp with itsglass bulb immersed in water in a beaker.filament lampto power supplywaterbeakerthermometerFig. 4.1The reading on the thermometer in the water is 19.0 °C.Only the glass of the lamp is in contact with the water and the electrical connections are completelyinsulated.The lamp is switched on.At the end of the experiment, the temperature of the water is 21.5 °C.(a) The mass of the water in the beaker is 600 g and the specific heat capacity of water is4200 J / (kg °C).(i) Show that the increase in the internal energy of the water is 6300 J.[3](ii) In the experiment, the lamp is switched on for 500 s. The power supplied to the filamentlamp is 13 W. The useful energy from the lamp is transferred as light. The energy thatincreases the temperature of the water is wasted energy.Determine the maximum possible efficiency of the filament lamp.maximum possible efficiency = ......................................................... [4]90625/41/M/J/23©UCLES 2023 [Turn over(b) The efficiency of the lamp is less than the value determined in (a)(ii).Suggest one reason for this.................................................................................................................................................................................................................................................................................................................................................................................................................................................... [1]

17 Researchers have developed a new type of filament lamp with an efficiency of 40%. Old-typefilament lamps have an efficiency of 5.0%. The two types of lamp produce the same useful outputpower.What is the ratio input power to new type of lampinput power to old type of lamp ?A 0.13 B 0.63 C 1.6 D 8.018 A student attempts to derive the formula for kinetic energy EK . She begins by considering anobject of mass m which is initially at rest. A constant force F applied to the object causes it toaccelerate to final velocity v in displacement s. The kinetic energy gained by the object is equal tothe work done on the object by the force F.Which equation would the student not need in order to derive the formula for EK ?A F = ma B W = Fs C E = Fs21 D v 2 = u 2 + 2as19 A metal wire obeys Hooke’s law and has a Young modulus of 2.0  10 11 Pa. The wire has anoriginal length of 1.6 m and a diameter of 0.48  10 –3 m.What is the spring constant of the wire?A 7.2  10 3 N m–1B 2.3  10 4 N m–1C 2.9  10 4 N m–1D 9.0  10 4 N m–120 A wire is being stretched by a tensile force.Which statement about the elastic limit must be correct?A The deformation is plastic after the elastic limit has been reached.B The deformation is plastic until the elastic limit is reached.C The extension is proportional to the tensile force after the elastic limit has been reached.D The extension is proportional to the tensile force until the elastic limit is reached.21 Which statement is correct for all types of progressive wave?A The distance from a peak to the next trough is equal to a wavelength.B They can be demonstrated in ripple tanks.C They consist of vibrating atoms.D They transfer energy from one position to another

How do you determine the difference between the Wet-Bulb and Dry-bulb Temperatures?

An energy-efficient light bulb transforms 100 J of input energy into 75 J of light energy. Another 25 J of heat energy is produced as waste.Calculate the light bulb's energy efficiency.25%50%75%100%

Compare the function of incandescent and fluorescent light bulbs and how this affects their efficiency.

Describe how the student could use her circuit to investigate how the currentthrough a filament lamp affects its resistance