Advertisements
Advertisements
प्रश्न
Advertisements
उत्तर
Factors on which the resistance of a conductor depends are:
(i) Nature of conductor: different materials have different concentration of free electrons and therefore resistance of a conductor depends on its material.
(ii) Length of conductor: Resistance of a conductor is directly proportional to the length of a conductor.
(iii) Area of cross-section of a conductor: Resistance of a conductor is inversely proportional to the area of cross-section of the uniform wire.
(iv) Temperature of conductor: In general for metallic conductors, higher the temperature larger is the resistance.
Materials which allow electric charges to flow through them easily are known as conductors. E.g. metals and materials which do not allow the electric charge to flow through them are known as insulators. E.g. rubber, dry wood etc.
APPEARS IN
संबंधित प्रश्न
In the circuit shown below, the voltmeter reads 10 V.

(a) What is the combined resistance?
(b) What current flows?
(c) What is the p.d. across 2 Ω resistor?
(d) What is the p.d. across 3 Ω resistor?
The figure given below shows an electric circuit in which current flows from a 6 V battery through two resistors.
- Are the resistors connected in series with each other or in parallel?
- For each resistors, state the p.d. across it.
- The current flowing from the battery is shared between the two resistors. Which resistor will have bigger share of the current?
- Calculate the effective resistance of the two resistors.
- Calculate the current that flows from the battery.
Christmas tree lamps are usually wired in series. What happens if one lamps breaks?
How do you think the brightness of two lamps arranged in parallel compares with the brightness of two lamps arranged in series (both arrangements having one cell)?
Define the following:
Electromotive force
Find the effective resistance in the following circuit diagrams (Fig.):

Explain with the help of a diagram how does 'short circuiting' occur in an electric kettle.
Define the term kilowatt - hour and state its value in S.I. unit.
State the conditions for the flow of charge in a circuit from one point to the other.
