Electricity and Circuits - SS1 Physics Past Questions and Answers - page 3
Describe the behaviour of current, voltage, and resistance in a series circuit. Explain why the current remains the same throughout the circuit and how the total resistance is calculated.
In a series circuit, the current passing through each component is the same. This is because there is only one path for the current to flow, and the current encounters the same resistance in each component. According to Ohm's Law (V = IR), the voltage across each component is directly proportional to its resistance. As a result, the total voltage of the circuit is divided among the components based on their resistances.
The total resistance in a series circuit is calculated by summing up the individual resistances of each component. This is because the total resistance is equivalent to the cumulative effect of all the resistances encountered by the current in the circuit.
Which of the following quantities is measured in watts?
Voltage
Current
Power
Energy
The formula for calculating electric power is:
Power = Voltage × Current
Power = Voltage / Current
Power = Current / Voltage
Power = Voltage + Current
If a device has a voltage of 120 V and a current of 2 A, what is the power consumed by the device?
60 W
120 W
240 W
480 W
Electric energy is measured in:
Volts
Amps
Watts
Joules
The energy consumed by a device over a period of time can be calculated by:
Energy = Power / Voltage
Energy = Power × Voltage
Energy = Power / Time
Energy = Power × Time
A 100 W light bulb is left on for 5 hours. How much energy does it consume?
50 Wh
100 Wh
500 Wh
1000 KW
The power rating of an electrical appliance indicates:
How much energy the appliance consumes
How long the appliance will last
How much current the appliance draws
The maximum power the appliance can handle
A light bulb has a power rating of 60W. If it is left on for 4 hours, how much energy does it consume?
To calculate the energy, we can use the formula E = P × t, where E is the energy, P is the power, and t is the time.
Plugging in the given values, we get E = 60W × 4h = 240Wh.
A motor has a power consumption of 500W. If it operates for 2.5 hours, how much energy does it consume?
To calculate the energy, we can use the formula E = P × t, where E is the energy, P is the power, and t is the time.
Plugging in the given values, we get E = 500W × 2.5h = 1,250Wh.