Q1.
Which physical quantity remains constant in a series combination.
Q2.
Which physical quantity remains constant in a parallel combination.
Q3.
Write the formula for the equivalent resistance for three resistance R1, R2 and R3 connected in series.
Q4.
Write the formula for the equivalent resistance for three resistance R1, R2 and R3 connected in parallel.
Q5.
Why is the series arrangement not used for domestic circuits? (write two points)
Q6.
State Joule’s law of heating.
Q7.
State two practical application of heating effect of electric current.
Q8.
Define electric power.
Q9.
Define 1 watt of power.
Q10.
Five resistors of 1 ohm each are connected in series to a 5 V battery. Determine the amount of current flowing in the 2nd resistor.
Q11.
Two unequal resistances are connected in series. If you are not provided with any other parameters, (eg: numerical values of V, I, and R). What can be said about the current used by each one of them? Justify your answer.
Q12.
In an electrical circuit two resistors of 2Ω and 4Ω respectively are connected in series to a 6 V battery.
(a) Determine the equivalent resistance.
(b) Determine the current drawn from the battery.
Q13.
How can three resistors of resistances 2 Ω, 3 Ω, and 6 Ω be connected to give a total resistance of 4 Ω ?
Q14.
What is (a) the highest, (b) the lowest total resistance that can be secured by combinations of four coils of resistance 4 Ω, 8 Ω, 12 Ω, 24 Ω ?
Q15.
100 J of heat is produced each second in a 4 Ω resistance. Find the potential difference across the resistor.
Q16.
Why does the cord of an electric heater not glow while the heating element does?
Q17.
An electric bulb is connected to a 220 V generator. The current is 0.50 A. What is the power of the bulb?
Q18.
Why is the tungsten used almost exclusively for filament of electric lamps?
Q19.
Why are the conductors of electric heating devices, such as bread-toasters and electric irons, made of an alloy rather than a pure metal?
Q20.
A student made a circuit as shown below in order to measure the current through the lamps.
(a) Identify the type of combination in which the two lamps are joined.
(b) Spot the mistake made by the student in the circuit.
(c) Calculate the equivalent resistance of the circuit after resolving the mistake.
