Which unit is the same as a volt?

5054_s19_qp_11

MCQ

2019

Paper 1, Variant 1

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A circuit includes a thermistor and a light-dependent resistor (LDR). The resistance of the thermistor and the resistance of the LDR both increase. Which changes cause this?

5054_w17_qp_12

MCQ

2017

Paper 1, Variant 2

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Which circuit contains a cell, a light-emitting diode and a fixed resistor?

5054_s05_qp_1

MCQ

2005

Paper 1, Variant 0

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A lamp is connected in series with a light-dependent resistor (LDR) and a battery. The barrier shields the LDR from the lamp. barrier When low intensity light falls on the LDR, the lamp glows dimly. If the light intensity on the LDR increases, what happens to the lamp?

5054_s09_qp_1

MCQ

2009

Paper 1, Variant 0

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The current / voltage graphs are for different electrical components. current voltage current voltage current voltage Which graph is for a resistor at constant temperature and which is for a filament lamp?

5054_s12_qp_12

MCQ

2012

Paper 1, Variant 2

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In a darkened room, a 1000 Ω resistor and a light-dependent resistor (LDR) are connected in series with a 12 V power supply. 1000 Ω LDR + – 12 V power supply The curtains are opened and light falls on the LDR. What happens to the voltage across the LDR?

5054_s13_qp_12

MCQ

2013

Paper 1, Variant 2

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A torch contains a filament lamp connected to a battery. The battery contains four 1.5 V cells connected in series. shows the current/potential difference graph for the filament lamp. potential difference / V current / mA State what is meant by the potential difference (p.d.) across the lamp. shows that the current in the lamp is not proportional to the p.d. 1. State how shows this. 2. Suggest why the current is not proportional to the p.d. The lamp is at normal brightness and there is a p.d. of 6.0 V across the lamp. 1. Use to find the current in the lamp. current = 2. Calculate the charge that passes through the lamp in 2.0 hours. charge = 3. The battery in the torch is able to keep the lamp lit for 2.0 hours. Estimate the initial energy stored in the battery. energy = 4. Explain why your value is only an estimate. Suggest and explain an advantage of using two cells in parallel rather than a single cell. Another torch contains a light-emitting diode (LED) instead of a filament lamp. The battery in the torch uses four 1.5 V cells, some in series and some in parallel. The p.d. across the LED when in operation is 3.0 V. In the space below, draw a circuit diagram showing how the four cells, a switch and the LED are connected.

5054_s14_qp_21

THEORY

2014

Paper 2, Variant 1

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Which symbol is used for a light-dependent resistor?

5054_s18_qp_12

MCQ

2018

Paper 1, Variant 2

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shows a circuit diagram containing a 2000 Ω resistor of constant resistance and a thermistor. thermistor 12 V 2000 Ω At one temperature, the resistance of the thermistor is 1200 Ω. Calculate the potential difference (p.d.) across the 2000 Ω resistor at this temperature. p.d. = Explain why the p.d. across the 2000 Ω resistor increases when the temperature increases. The circuit in can be adapted to enable a lamp to switch on and off automatically. shows the circuit adapted using a relay and shows the circuit adapted using a transistor. In both cases, the lamp switches on when the temperature of the thermistor increases. thermistor lamp relay switch relay coil thermistor transistor lamp EITHER Describe what happens inside the relay in that causes the lamp to switch on. OR Describe how the circuit and transistor in cause the lamp to switch on.

5054_s19_qp_21

THEORY

2019

Paper 2, Variant 1

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A student uses a transformer to light a filament lamp using a 230 V a.c. supply. The lamp has a maximum voltage rating of 6.0 V. 230 V 300 turns 20 turns What happens when the circuit is switched on?

5054_s21_qp_11

MCQ

2021

Paper 1, Variant 1

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