Electrical resistivity of some substances at 20 ° C are given below Silver 1 . 60 × 10 8 Ω m Copper 1 . 62 × 10 8 Ω m Tungsten 5 . 20 × 10 8 Ω m Iron 10 . 0 × 10 8 Ω m Mercury 94 . 0 × 10 8 Ω m Nichrome 100 × 10 8 Ω m Answer the following questions in relation to them: (i) Among silver and copper, which one is a better conductor? Why? (ii) Which material would you advise to be used in electrical heating devices? Why?

(i) Among silver and copper, silver is a better conductor because it’s resistivity is lesser than copper. (ii) Nichrome would be advised to be used in electrical heating devices because it has a high resistivity and would produce heat much faster than other elements.

MEDIUM

10th CBSE

IMPORTANT

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What do the following symbols mean in circuit diagrams?

(i)

(ii)

Important Questions on Electricity

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10th CBSE

IMPORTANT

SCIENCE PHYSICS>Chapter 3 - Electricity>MOCK TEST QUESTION PAPER>Q 25

An electric circuit consisting of a 0.5 m long nichrome wire XY, an ammeter, a voltmeter, four cells of 1.5 V each and a plug key was set up.
(i) Draw a diagram of the electric circuit to study the relation between the potential difference maintained between the points ‘X’ and’ Y’ and the electric current flowing through XY.
(ii) Following graph was plotted between V and I values: What would be the values of V/I ratios when the potential difference is 0.8 V, 1.2 V and 1.6 V respectively? What conclusion do you draw from these values?

Question Image

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SCIENCE PHYSICS>Chapter 3 - Electricity>MOCK TEST QUESTION PAPER>Q 26

Define the term ‘volt’.

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IMPORTANT

SCIENCE PHYSICS>Chapter 3 - Electricity>MOCK TEST QUESTION PAPER>Q 26

State the relation between works, charge and potential difference for an electric circuit. Calculate the potential difference between the two terminals of a battery if

100 joules

of work is required to transfer

20 coulombs

of charge from one terminal of the battery to the other.

HARD

10th CBSE

IMPORTANT

SCIENCE PHYSICS>Chapter 3 - Electricity>MOCK TEST QUESTION PAPER>Q 27

What is Joule’s heating effect? How can it be demonstrated experimentally? List its four applications in daily life

HARD

10th CBSE

IMPORTANT

SCIENCE PHYSICS>Chapter 3 - Electricity>MOCK TEST QUESTION PAPER>Q 28

Explain with the help of a labelled circuit diagram, how you will find the resistance of a combination of three resistors, of resistance

R_{1}, R_{2} and R_{3}

, joined in parallel. Also mention how you will connect the ammeter and the voltmeter in the circuit when measuring the current in the circuit and the potential difference across one of the three resistors of the combination.

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10th CBSE

IMPORTANT

SCIENCE PHYSICS>Chapter 3 - Electricity>MOCK TEST QUESTION PAPER>Q 29

What is meant by saying that the potential difference between two points is

1 volt

? Name a device that helps to measure the potential difference across a conductor.

MEDIUM

10th CBSE

IMPORTANT

SCIENCE PHYSICS>Chapter 3 - Electricity>MOCK TEST QUESTION PAPER>Q 29

Why does the connecting cord of an electric heater not glow hot while the heating element does?

MEDIUM

10th CBSE

IMPORTANT

SCIENCE PHYSICS>Chapter 3 - Electricity>MOCK TEST QUESTION PAPER>Q 29

Electrical resistivity of some substances at $20 ° C$ are given below

Question Image

Silver	$1.60 \times 10^{8} Ω m$
Copper	$1.62 \times 10^{8} Ω m$
Tungsten	$5.20 \times 10^{8} Ω m$
Iron	$10.0 \times 10^{8} Ω m$
Mercury	$94.0 \times 10^{8} Ω m$
Nichrome	$100 \times 10^{8} Ω m$

Answer the following questions in relation to them:
(i) Among silver and copper, which one is a better conductor? Why? (ii) Which material would you advise to be used in electrical heating devices? Why?

What do the following symbols mean in circuit diagrams? (i) (ii)

Important Questions on Electricity

Learn and Prepare for any exam you want !

What do the following symbols mean in circuit diagrams?

(i)

(ii)