Advertisements
Advertisements
प्रश्न
Why do telephone wires sag in summer ?
Advertisements
उत्तर
The telephone wires will sag in summer due to expansions and will break in winter due to contraction.
Therefore, while putting up the wires between the poles, care is taken that in summer they are kept slightly loose so that they may not break in winter due to contraction.
While in winter they are kept light so that they may not sag too much in summer due to expansion.
APPEARS IN
संबंधित प्रश्न
Write true or false for a given statement.
Heat flows from a body at a high temperature to a body at a low temperature when they are kept in contact.
Fill in the blank
In a thermometer, the commonly used liquid is _______
Fill in the blank
The temperature of boiling water is _______
Name the instrument used to measure the temperature of a body.
The fig. shows a glass tumbler containing hot milk which is placed in a tub of cold water. State the direction in which heat will flow.
Iron rims are heated before they are fixed on the wooden wheels. Explain the reason.
Describe one experiment to show that liquids expand on heating.
State which expands more, when heated to the same temperature : solid, liquid or gas ?
What are the land and sea breezes? Explain their formation.
Explain the following effects of heat.
Expansion
