Question no 7, 8 and 9, the given two statements are assertion and reason. Select the correct answer to these questions
from the options given below.
1) Both assertion and reason are true, and reason is correct explanation of the assertion.
2) Both assertion and reason are true, but reason is not the correct explanation of the assertion.
3) Assertion is true but reason is false.
4) Assertion is false, but reason is true.
Q7. Assertion: Alloys are commonly used in electrical heating devices like electrical iron and heater.
Reason: Resistivity of an alloy is generally higher than that of its constituent metals, but the alloy has lower melting point than
their constituent metals.
Q8. Assertion: The disposal of waste we generate is causing serious environmental problems.
Reason: We should reduce the waste generated.
Q9. Assertion: Electromagnets are made of soft iron.
Reason: The strength of an electromagnet is increased by increasing the current flowing through the solenoid coil.
Answers
Answer:
Plants, animals, and microbes are interdependent. This makes the ecosystem self-regulating and self-sustaining with all the components of the ecosystem. So, the correct answer is option A. Both assertion and reason are true and reason is the correct explanation of assertion
So, the correct answer is option A. Both assertion and reason are true and reason is the correct explanation of assertion
B - Both A and R are true but R is NOT the correct explanation of A. C - A is true but R is false. ... Hence we can say that the assertion and reason both are correct and reason is the correct explanation of assertion. Hence our answer option will be A.
B - Both A and R are true but R is NOt
the correct explanation of A. C - A is true but R is false. D - A is false but R is true. ... Hence we can say that the assertion and reason both are correct and reason is the correct explanation of assertion.
Assertion- Alloys are commonly used in electrical heating devices like electric iron and heater. Reason- Resistivity of an alloy is generally higher than that of its constituent metals but the alloys have low melting points than their constituent metals
Reason- Resistivity of an alloy is generally higher than that of its constituent metals but the alloys have low melting points than their constituent metals. ... So it has partial characteristics of metal and non metal.
Dumping of wastes in a haphazard and unscientific manner has a serious environmental impact. It leads to:
1. Degradation of land.
2. Pollution of drinking water,
3. Destruction of aquatic life,
4. Degradation of ground and surface water used for irrigation and industries,
5. Improper disposal of wastes causes soil, air and water pollution
Electromagnets are made of soft iron because soft iron has low retentivity and low coercive force or low coercivity. Soft iron is a soft magnetic material.