# Sample Paper

Time allowed : 3 hours

Max. Marks : 70

General Instructions:

1. All questions are compulsory
2. There are 30 questions in total. Questions 1 to 8 carry one mark each, 9 to 18 carry two marks each, 19 to 27 carry 3 marks each and 28 to 30 carry 5 marks each.
3. There is no overall choice, but internal choices are provided. You have to attempt only one choice in full.
4. Use of calculator is not permitted.
5. You may use the logarithm table, if required.

1. What is electrostatic shielding?

2. Identify the carbon resistor whose colour code is green, blue, red and gold.

3. Energy of a charged particle

## The mechanism of operation in a capacitor

The DC doesnt flow through capacitor. I thought it was because the electrons jus get saturated on one side and are lost on other side, such that it can’t take or give up anymore or plausibly due to voltage developed across it whereas in AC as directions keep changing, saturation doesnt occur. But it if [...]

## What is meant by charge on a capacitor?

“What is meant by charge on a capacitor?”

Answer: As we know, a simple capacitor (say a parallel plate capacitor) consists of two plates parallel

• Various types of capacitor
• Factors Affecting Capacitance
• Capacitor Networks
• Charging and Discharging Capacitors

## CBSE Question Paper 2007

SET -1

1. In a series LCR circuit, the voltages across an inductor, a capacitor and a resisitor are 30 V, 30V and 60 V respectively. What is the phase

## IMPORTANT FIVE MARKS QUESTIONS FOR CLASS XII

1. Derive an expression for the Electric field at a point on the (i) axial line and (ii) equatorial line of an electric dipole
2. Describe the principle construction and working of Van de Graff Generator.
3. State Gauss’ theorem and apply it to find the electric field at a point due to
1. A point charge
2. A line of charge
3. A plane sheet of charge
4. A charged spherical conducting shell
Derive expression for the potential energy of a system of point charges. Derive expression for the torque on a dipole in a uniform electric field. Derive expression for the work done in turning a dipole in a uniform electric field. Derive an expression for the potential energy of a dipole in a uniform electric field. Explain the principle of a parallel plate capacitor Derive an expression for the capacitance of a parallel plate capacitor.

10.  Derive an expression for the effective capacitance when three capacitors are connected in (i) series (ii) parallel

11.  Derive an expression for the energy stored in a parallel plate capacitor.

12.