Resistivity

Q.

What are the advantages and disadvantages of parallel and series circuit?

Q.

Resistance of a metal wire of length 1m is 26 ohm at room temperature. If diameter of wire is 0.3 mm, find the resistivity of the wire.

Q.

Compute the heat generated while transferring $96000\mathrm{coulombs}$ of charge in $1\mathrm{hour}$ through a potential difference of $50\mathrm{V}$.

Q.

Define the term specific resistance and state its S.I. unit.

Q.

What is Resistivity?

Q.

What is the dimensional formula of resistivity?

Q.

Electrical resistivity of a given metallic wire depends upon

1. its length

2. its thickness

3. its shape

4. nature of the material

Q.

The dimensions of electrical conductivity are,

1. $\left[M^{-1}{L}^{-3}{T}^3{A}^2\right]$

2. $\left[M^1{L}^3{T}^3{A}^2\right]$

3. $\left[M^1{L}^3{T}^3{A}^{-2}\right]$

4. $\left[M^2{L}^3{T}^3{A}^2\right]$

Q.

Calculate the resistance of 2 km long copper wire of radius 2mm if resistivity of copper = 1.72 × 10 ^ - 8

Q.

A wire is stretched by 10 percentage of its original length. Calculate the percentage change in its resistance.

Q.

Why connecting wires are made from Copper?

Q.

What is a pure and impure semiconductor?

Q.

Alloys like manganin and constantan are used for making standard resistance coils as they have________.

Q.

An electric bulb rated as $40W,220V$. Calculate its resistance.

Q.

What is the cause of resistance?

Q. Find the resistance of a hollow cylindrical pipe of length 1 m whose inner and outer radii are 10 cm and 20 cm respectively. Assume that the cylindrical pipe is made of a material of resistivity $2\times {10}^{-8}\Omega m$.

1. $0.21m\Omega$

2. $0.21\Omega$

3. $0.21\mu \Omega$

4. $21\Omega$

Q. With the increase in temperature, the resistance of a pure metal ____.

1. increases

2. decreases

3. does not change

4. first increases and then decreases

Q.

Which Is The best conductor Of electricity?

Q. A uniform wire of resistance $100\Omega$ is melted and recasted into a wire of length twice that of the original. The resistance of the new wire is _____.

1. $100\Omega$
2. $200\Omega$
3. $400\Omega$
4. $300\Omega$

Q.

A wire of length L and resistance R is stretched so that its length its doubled. How will

(i) Resistance change (ii) Resistivity change?

1. Resistance increases 2 times; resistivity remains same

2. Resistance increases 4 times; resistivity remains same

3. Resistance decreases 4 times; resistivity increases 2 times

4. Resistance decreases 2 times; resistivity increases 4 times

Q.

The electrical resistivity of four materials A , B, C and D are given as

A=110×10^-8 ohm metre

B=1×10¹⁰ ohm metre

C=10×10^-8 ohm metre

D=2.3×10³ ohm metre

which material is

1) good material

2) resistor

3) insulator

4) semi-conductor

Give reasons for your answer.

Q. A bullet fired into a wooden block loses half of its velocity after penetrating $40\text{cm}.$ It comes to rest after penetrating a further distance of

1. $\frac{22}{3}\text{cm}$
2. $\frac{20}{3}\text{cm}$
3. $\frac{22}{5}\text{cm}$
4. $\frac{40}{3}\text{cm}$

Q.

Define rho

Q.

How does the specific resistance of a semiconductor change with the increase in temperature?

Q.

Write the unit of Electrical resistivity.

Q.

Name a material which is used for making the standard resistaor. Give a reason for your answer.

Q.

What is electrical resistivity of a material what is its unit ? Study the factors on which the resistance of conducting wire depends?

Q.

(a) Define resistivity. Write an expression for the resistivity of a substance. Give the meaning of each symbol which occurs in it.
(b) State the SI unit of resistivity.
(c) Distinguish between resistance and resistivity.
(d) Name two factors on which the resistivity of a substance depends and two factors on which it does not depend.
(e) The resistance of a metal wire for length $\text{1 m}$ is $26ohm$ at $20^o$ C, If the diameter of the wire is $\text{0.3 mm}$, what will be the resistivity of the metal at that temperature?

Q.

Why are copper wires used as connecting wires?

Q.

1. What Does Modem Stand For