Question
Explain radiation.
✓
Answer
The mode of transfer of heat energy in which no medium is needed to transfer heat from a hotter body to a colder body is called radiation. The heat from the sun comes to the earth without any medium thereby using the mode of radiation. Also, all objects exchange heat with their surroundings through the process of radiation.
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Q.1. What happens when the length increases?
(a) Time period decreases
(b) Time period increases
(c) No change
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→In an experiment, Riya uses a pendulum of different lengths to observe time periods.
Q.1. What happens when the length increases?
(a) Time period decreases
(b) Time period increases
(c) No change
(d) Speed increases
Q.2. Which factor affects the pendulum's time period most?
(a) Mass$\quad$(b) Shape
(c) Length$\quad$(d) Material
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Which of the following are not correct?
(a) The basic unit of time is second.
(b) Every object moves with a constant speed.
(c) Distances between two cities are measured in kilometres.
(d) The time period of a given pendulum is not constant.
(e) The speed of a train is expressed in $m / h$.
→(a) The basic unit of time is second.
(b) Every object moves with a constant speed.
(c) Distances between two cities are measured in kilometres.
(d) The time period of a given pendulum is not constant.
(e) The speed of a train is expressed in $m / h$.
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