2nd Year Physics Chapter 13 Online Preparation ( current electricity)

Question # 1

Briefly describe the current through a metallic conductor and drift velocity.

Ans 1: In a metallic conductor,free electron are in random motion with the speed of several hundred km/s at the room temperature.If the ends of the wire are connected to the battery the free electrons are experience a force and directed to move in the electric field direction.The accelerating electrons keep on colliding with atoms of the conductors and transfer their energy to the lattice with the result that the electrons acquire an average velocity called drift velocity.The drift velocity is of the order of 10^-3.A steady current is establish in the wire.

Question # 2

What is meant by tolerance of resistors?

Ans 1: Tolerance is the measure of possible variation from the marked value,A gold band has +-5% tolerance ,silver has +-10% and no band at all wounf mean a +-20 tolerance.

Question # 3

A potential difference is applied across the ends of a copper wire,What is the effect on the drift velocity of free electrons by decreasing the length and temperature of the wire?

Ans 1: By decreasing the length and temperature of wire the value of resistance in the wire also decrease which cause an increase in the value of current,Hence the drift velocity of free electrons also increase.

Question # 4

What is the negative coefficient of temperature?

Ans 1: If the resistance of a substance decrease with an increase in temperature ,then it is termed as negative coefficient of temperature,For example ,silicon and germanium have negative coefficient of temperature.

Question # 5

Differentiate between conventional and non-conventional current.

Ans 1: Conventional Current: The current flow die to positive charges from a point at higher potential to a point at lower potential is called conventional current.
Ans 2: Non-Conventional Current: The amount of electric charge that flow through a cross section of a conductor per unit time is known as electric current.It is also known as non-conventional current.

Question # 6

What is the effect on drift velocity of free electrons by increasing potential difference?

Ans 1: By an increase in potential difference,drift velocity also increase.Because by increasing potential difference ,the current also increase .

Question # 7

Name some effects of current.

Ans 1: Some effects are :
1. Heating effects
2. Magnetic effect
3. Chemical effect

Question # 8

Write about any two sources of Current.

Ans 1:
1. Electric generators convert mechanical energy into the electrical energy.
2. Solar cells convert sunlight directly into electrical energy.
3. Thermocouples convert heat energy into electrical energy.

Question # 9

What is thermistor? Gives its two applications.

Ans 1: Thermistors are heat sensitive resistors.Thermistors with positive temperature coefficient of resistance as well as negative temperature coefficient of resistance are available.They are used for accurate measuring of temperature up to 10K.They are used as temperature sensors.

Question # 10

Give two substance having negative temperature coefficient.Also define the temperature coefficient.

Ans 1: The temperature coefficient of a resistance is defined as fractional change in resistance per kelvin rise in temperature.Its unit is K^-1.Substance like Ge and Si have negative temperature coefficient.

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2nd Year Physics Chapter 13 Online Preparation

Online Short Questions For Chapter 2 "12th Class Physics Chapter 2 Short Questions Preparation "

Physics - 12th Class Physics Chapter 2 Short Questions Preparation

Briefly describe the current through a metallic conductor and drift velocity.

What is meant by tolerance of resistors?

A potential difference is applied across the ends of a copper wire,What is the effect on the drift velocity of free electrons by decreasing the length and temperature of the wire?

What is the negative coefficient of temperature?

Differentiate between conventional and non-conventional current.

What is the effect on drift velocity of free electrons by increasing potential difference?

Name some effects of current.

Write about any two sources of Current.

What is thermistor? Gives its two applications.

Give two substance having negative temperature coefficient.Also define the temperature coefficient.

Prepare Complete Set Wise Questions For Chapter 2 "12th Class Physics Chapter 2 Short Questions Preparation "

Set 1

Set 2

Set 3

12th Class Physics Chapter 2 Short Questions Preparation - Set 1

Briefly describe the current through a metallic conductor and drift velocity.

What is meant by tolerance of resistors?

A potential difference is applied across the ends of a copper wire,What is the effect on the drift velocity of free electrons by decreasing the length and temperature of the wire?

What is the negative coefficient of temperature?

Differentiate between conventional and non-conventional current.

What is the effect on drift velocity of free electrons by increasing potential difference?

Name some effects of current.

Write about any two sources of Current.

What is thermistor? Gives its two applications.

Give two substance having negative temperature coefficient.Also define the temperature coefficient.

12th Class Physics Chapter 2 Short Questions Preparation - Set 2

What is the effect on drift velocity of free electrons by increasing potential difference?

How a wheatstone bridge is used to determine an unknown resistance?

Give two substance having negative temperature coefficient.Also define the temperature coefficient.

What is the conventional current? How does it differs from electric current?

State Ohm's law and basic principle of electroplating.

Define resistivity and electrolysis.

Do two long and parallel current carrying wires attract each other?

What is short circuit and open circuit mean to you?

Briefly describe the current through a metallic conductor and drift velocity.

Write about any two sources of Current.

12th Class Physics Chapter 2 Short Questions Preparation - Set 3

How can rheostat be used as potential divider?

What is ohmic and non ohmic devices with example.

A voltmeter can not read the exact EMF of the cell.Why?

How a wheatstone bridge is used to determine an unknown resistance?

Write about any two sources of Current.

Why does the resistance of a conductor rise with a temperature?

What does the equation H=I2Rt show?

What is wheat stone bridge?

Differentiate between resistance and resistivity.Give their unit.

What is meant by tolerance?

12th Class Physics Ch 13 Preparation

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What does the equation H=I²Rt show?