32 The circuit diagrams show two lamps X and Y each connected to a cell. The current in lamp X is0.50 A and its resistance is 9.6 . The current in lamp Y is 3.0 A and its resistance is 1.2 .0.50 A lamp X9.6 3.0 A lamp Y1.2 What is the ratio YlampinpowerXlampinpower ?A 0.22 B 0.75 C 1.3 D 4.533 The intensity of light incident on a light-dependent resistor (LDR) is increased. The temperatureof a thermistor is increased. In each case, the current in the component is maintained at aconstant value.What happens to the potential difference across each component?LDR thermistorA increases increasesB increases decreasesC decreases increasesD decreases decreases34 An iron wire has length 8.0 m and diameter 0.50 mm. The wire has resistance R.A second iron wire has length 2.0 m and diameter 1.0 mm.What is the resistance of the second wire?A 16R B 8R C 2R D R35 A cell with constant electromotive force (e.m.f.) is connected across a fixed resistor. Over time,the internal resistance of the cell increases.Which change occurs as the internal resistance of the cell increases?A a decrease in the charge of each charge carrierB a decrease in the potential difference measured across the cellC an increase in the energy dissipated per unit time in the fixed resistorD an increase in the number of charge carriers leaving the cell per unit time

The hot resistance of a 240 V filament lamp is 960Ω. Find the current taken by the lamp and its power rating

35 The diagram shows a cell of electromotive force (e.m.f.) 3.0 V and internal resistance 4.7 connected across a lamp. The lamp has a resistance of 9.3 .4.7 9.3 3.0 VWhat is the power dissipated by the internal resistance of the cell?A 0.22 W B 0.43 W C 0.64 W D 1.0 W36 A circuit consists of a battery, a high-resistance voltmeter and four fixed resistors, as shown. Thebattery has an electromotive force (e.m.f.) of 15.0 V and negligible internal resistance.V24.0 6.0 6.0 9.0 15.0 VWhat is the reading on the voltmeter?A 3.0 V B 6.0 V C 9.0 V D 12.0 V

Question 4c The student obtains this graph for a filament lamp. Calculate the resistance of the lamp when the voltage is 6.0 V. Give the unit.

When the current flowing through a lamp is decreased by 2%, then the percentage change in the power consumed by the lamp will be Only one correct answerA.5.48%B.4.25%C.3.96%D.6.75%

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