The following table gives the resistivity of three samples: Sample Resistivity A 1 . 6 × 10 - 8 Ω m B 5 . 1 × 10 - 8 Ω m C 10 . 6 × 10 - 6 Ω m Which of them is suitable for heating elements of electrical appliances and why?

Sample C because it has the highest resistivity in the given range of resistors. Note: Sample C has highest resistivity and consequently highest resistance. Therefore, it will resist the flow of charges more, and lead to development of heat faster.

Following table gives the resistivity of three samples in Ω m Sample Resistivity A 1 . 6 × 10 - 8 B 7 . 5 × 10 - 7 C 44 × 10 - 6 Which of them is a good conductor? And which of them is an insulator? And why?

A is a good conductor with least resistivity. C is an insulator with maximum resistivity. Note: C has highest resistivity when compared to other samples. Since, resistivity is high, resistance of Sample C is high and hence it can be considered as an insulator.

E M B I B E

ESSENTIALS OF PHYSICS CLASS X>Chapter 3 - Electricity>Assignment-3>Q 17

EASY

10th CBSE

IMPORTANT

Earn 100

What is electrical resistivity?

Important Questions on Electricity

EASY

10th CBSE

IMPORTANT

ESSENTIALS OF PHYSICS CLASS X>Chapter 3 - Electricity>Assignment-3>Q 18

You have a metal, insulator and an alloy. Write these substances in the ascending order of their electrical resistivity.

EASY

10th CBSE

IMPORTANT

ESSENTIALS OF PHYSICS CLASS X>Chapter 3 - Electricity>Assignment-3>Q 19

Should the heating element of an electric iron be made of iron, silver or Nichrome wire?

EASY

10th CBSE

IMPORTANT

ESSENTIALS OF PHYSICS CLASS X>Chapter 3 - Electricity>Assignment-3>Q 20

Why do we use copper and aluminium wire for transmission of electric current?

EASY

10th CBSE

IMPORTANT

ESSENTIALS OF PHYSICS CLASS X>Chapter 3 - Electricity>Assignment-3>Q 21

A wire of resistivity '

ρ

' is pulled to doubled its length. What will be its new resistivity?

HARD

10th CBSE

IMPORTANT

ESSENTIALS OF PHYSICS CLASS X>Chapter 3 - Electricity>Assignment-3>Q 22

The voltage-current ( $V$ - $I$ ) graph of a metallic conductor at two different temperature $T_{1}$ and $T_{2}$ is shown in figure. At which temperature is the resistance higher?

Question Image

EASY

10th CBSE

IMPORTANT

ESSENTIALS OF PHYSICS CLASS X>Chapter 3 - Electricity>Assignment-3>Q 23

The following table gives the resistivity of three samples:

Sample	Resistivity
$A$	$1.6 \times 10^{- 8} Ω m$
$B$	$5.1 \times 10^{- 8} Ω m$
$C$	$10.6 \times 10^{- 6} Ω m$

Which of them is suitable for heating elements of electrical appliances and why?

EASY

10th CBSE

IMPORTANT

ESSENTIALS OF PHYSICS CLASS X>Chapter 3 - Electricity>Assignment-3>Q 24

Following table gives the resistivity of three samples in $(Ω m)$

Sample	Resistivity
$A$	$1.6 \times 10^{- 8}$
$B$	$7.5 \times 10^{- 7}$
$C$	$44 \times 10^{- 6}$

Which of them is a good conductor? And which of them is an insulator? And why?

EASY

10th CBSE

IMPORTANT

ESSENTIALS OF PHYSICS CLASS X>Chapter 3 - Electricity>Assignment-3>Q 25

The electrical resistivity of few materials is given below in ohm-meter. Which of these materials can be used for making element of a heating device?

Material	Resistivity (in ohm-metre)
A	$6.84 \times 10^{- 8}$
B	$1.60 \times 10^{- 8}$
C	$2.30 \times 10^{17}$
D	$1.00 \times 10^{- 6}$
E	$2.50 \times 10^{12}$
F	$4.40 \times 10^{- 8}$