Advertisements
Advertisements
Question
Name the following substances:
(i) Showing low resistivity,
(ii) Showing very high resistivity,
(iii) Showing moderate resistivity.
Advertisements
Solution
(i) Metals e.g. copper
(ii) Alloys e.g. Constantan
(iii) Semiconductors e.g. Germanium
APPEARS IN
RELATED QUESTIONS
Find the expression for resistors connected in series.
(i) Two sets A and B, of three bulbs each, are glowing in two separate rooms. When one of the bulbs in set A is fused, the other two bulbs also cease to glow. But in set B, when one bulb fuses, the other two bulbs continue to glow. Explain why this phenomenon occurs.
(ii) Why do we prefer arrangements of Set B for house circuiting?
How does the presence of impurities in a metal affect its resistance?
What is (a) highest, and (b)Ω lowest, resistance which can be obtained by combining four resistors having the following resistances?
4 Ω, 8 Ω, 12 Ω, 24 Ω
Name a substance of which the resistance remains almost unchanged by the increase in temperature.
Three resistors of 6.0 Ω, 2.0 Ω and 4.0 Ω are joined to an ammeter A and a cell of emf 6.0 V as shown in the following figure. Calculate :
- the effective resistance of the circuit.
- the reading of ammeter.
To increase the effective resistance in a circuit, the resistors are connected in _______________ .
Two resistors of 4Ω and 6Ω are connected in parallel to a cell to draw 0.5 A current from the cell.
Draw a labelled circuit diagram showing the above arrangement.
The resistance of the hot filament of the bulb is about 10 times the cold resistance. What will be the resistance of 100 W-220 V lamps, when not in use?
Show how you would connect three resistors, each of resistance 6 Ω, so that the combination has a resistance of 4 Ω.
