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(a) At every electricity point in the different rooms of a house, there is a potential difference of $220\ \text{V}$. How is this possible ? Write any one benefit of it.
(b) An electric heater rated $2\ \text{kW}$; $220\ \text{V}$ is used in a room having electric circuit of current rating of $5\ \text{A}$. What will happen when you switch on the circuit ? Justify your answer with reason.
(b) An electric heater rated $2\ \text{kW}$; $220\ \text{V}$ is used in a room having electric circuit of current rating of $5\ \text{A}$. What will happen when you switch on the circuit ? Justify your answer with reason.
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(a) • Because every electricity point is connected parallel to main board. ($\frac{1}{2}$ Mark)
• Benefits :
(i) Provides same potential difference to each appliance ($\frac{1}{2}$ Mark)
(ii) Every circuit has its own switch. If one appliance is fused/damaged other appliances will continue to work. (1 Mark)
[any one and any other ]
(b) • $\text{P=VI} \Rightarrow \text{I= P/V}$ ($\frac{1}{2}$ Mark)
$\text{I} = \frac{2000}{220}$ ($\frac{1}{2}$ Mark)
$\text{I} = 9.09 \text{ A}$
Fuse wire will melt because current drawn by heater is quite large as compared to rated value of current in the circuit. (1 Mark) (3 Marks)
• Benefits :
(i) Provides same potential difference to each appliance ($\frac{1}{2}$ Mark)
(ii) Every circuit has its own switch. If one appliance is fused/damaged other appliances will continue to work. (1 Mark)
[any one and any other ]
(b) • $\text{P=VI} \Rightarrow \text{I= P/V}$ ($\frac{1}{2}$ Mark)
$\text{I} = \frac{2000}{220}$ ($\frac{1}{2}$ Mark)
$\text{I} = 9.09 \text{ A}$
Fuse wire will melt because current drawn by heater is quite large as compared to rated value of current in the circuit. (1 Mark) (3 Marks)