Advertisements
Advertisements
प्रश्न
Point out two main disadvantages of ‘Tree System’.
उत्तर
The three main disadvantages are:
(i) Longer length of wire is required for wiring different rooms in a house. Since all circuits start from the main distribution board and so it is comparatively more Expensive.
(ii) If fuse blows off in any part of the building, it disconnects all the appliances in the circuit.
APPEARS IN
संबंधित प्रश्न
Define watt-hour. How many joules are equal to 1 watt-hour?
An electric fan runs from the 230 V mains. The current flowing through it is 0.4 A. At what rate is electrical energy transferred by the fan?
Electrical power p is given by the expression P = (Q × V) ÷ time. Express the power P in terms of current and resistance explaining the meaning of symbols used there in.
Name the S.I unit of electrical energy. How is it related to Wh?
1kWh = …….. J
The diagram below shows a magnetic kept just below the conductor AB which is kept in North South direction.
(i) In which direction will the needle deflect when the key is closed ?
(ii) Why is the deflection produced ?
(iii) What will be the change in the deflection if the magnetic needle is taken just above the conductor AB ?
(iv) Name one device which works on this principle.
Which material is the calorimeter commonly made of? Give one reason for using this material.
With reference to the diagram shown below calculate:
(i) The equivalent resistance between P and Q.
(ii) The reading of ammeter.
(iii) The electrical power between P and Q.
A battery of e.m.f. 12V and internal resistance 1.6 Ω is connected to two resistors of 4Ω and 6Ω connected in parallel. Calculate:
(i) the current drawn from the battery,
(ii) the power dissipated in each resistor,
(ii)the total power supplied by the battery.
A student wants to use an electric heater, an electric bulb and an electric fan simultaneously.
How should these gadgets be connected with the mains? Justify your answer giving three reasons.
