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

Question # 1

What are non ohmic devices?Give two examples.

Ans 1: Those devices which don't obey the Ohm's law are called non-ohmic devices.Their current-voltage graphic is not a straight line.For example ,filament bulb and semiconductor diodes.

Question # 2

What is meant by tolerance?

Ans 1: Tolerance means the possible variation from the marked value.

Question # 3

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 # 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

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

Ans 1: When a voltmeter is connected across a cell,it will draw some current from the cell and small potential drop takes place due current flowing through the internal resistance of the cell.As a result the actual emf of the cell decrease and the voltmeter cannot read exact value.

Question # 6

How the heating effects produce when current flows through the conductor?

Ans 1: During their motion free electrons collide frequently with the atoms of metal,on each collision they transfer some of their kinetic energy to the atime with which they collide.And these collisions produce heating effect in the wire.

Question # 7

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 # 8

What is short circuit and open circuit mean to you?

Ans 1: when switched is close and current is passing through the circuit,It is called closed circuit and in this situation resistance is zero whereas the circuit is said to be open if it has infinite resistance and no current is passing through it.

Question # 9

Name any four source of current.

Ans 1: Source of current are
1. Cells
2. Electric generators
3. Thermocouples
4. Solar cells

Question # 10

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

Ans 1: Wheatstone bridge is an especially designed electrically circuit used to calculate the accurate value of any unknown resistance.It consists of four resistance,a galvanometer, a battery and a switch connected.When the switch is closed current pas through the galvanometer and then the three known resistance R₁,R₂and R₃are adjusted in such a way that galvanometer show no deflection,In this balanced condition the fourth unknown resistance R₄can be calculated by using this relation.R₁/R₂=R₃/R₄.

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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

What are non ohmic devices?Give two examples.

What is meant by tolerance?

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

What is the negative coefficient of temperature?

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

How the heating effects produce when current flows through the conductor?

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

What is short circuit and open circuit mean to you?

Name any four source of current.

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

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

What are non ohmic devices?Give two examples.

What is meant by tolerance?

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

What is the negative coefficient of temperature?

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

How the heating effects produce when current flows through the conductor?

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

What is short circuit and open circuit mean to you?

Name any four source of current.

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

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

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 does the equation H=I2Rt show?

What is meant by tolerance of resistors?

How can rheostat be used as potential divider?

What are non ohmic devices?Give two examples.

What is thermistor? Gives its two applications.

What is ohmic and non ohmic devices with example.

Define Electromotive force and Terminal potential difference.

Does the bends in wire effect its electrical resistance?

Differentiate between conventional and non-conventional current.

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

Differentiate between conventional and non-conventional current.

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

What is meant by tolerance?

What are non ohmic devices?Give two examples.

How can rheostat be used as potential divider?

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

What is thermistor? Gives its two applications.

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

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

State Ohm's law and write its formula.

12th Class Physics Ch 13 Preparation

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What does the equation H=I²Rt show?