CBSE Class 10th Science | Chapter 15. Our Environment | Solved Exercises

In Text Questions | Page 257 |Chapter 15. Our Environment | CBSE Class 10th Science

Question 1. Why are some substances biodegradable and some non-biodegradable?

Answer. Some substances can be acted upon by the micro organisms and broken down into simple substances. Such substances are called biodegradable.
Some substances are inert and cannot be acted upon by the microorganisms and do not breakdown into simple substances. Such substances are called non- biodegradable.

CBSE Class 10th Science | Chapter 14. Sources of Energy | Solved Exercises

Question 1. A solar water heater cannot be used to get hot water on
(a) a sunny day.
(b) a cloudy day.
(c) a hot day.
(d) a windy day.

Answer. (b) a cloudy day.

CBSE Class 10th Science | Chapter 13. Magnetic Effects of Electric Current | Solved Exercises

Question 1. Which of the following correctly describes the magnetic field near a long straight wire?
(a) The field consists of straight lines perpendicular to the wire.
(b) The field consists of straight lines parallel to the wire.
(c) The field consists of radial lines originating from the wire.
(d) The field consists of concentric circles centred on the wire.

Answer. (d) The field consists of concentric circles centred on the wire.