04:25

5. the figure shows a series LCR circuit connected to a variable frequency 200 Vac source

02:36

4. When an alternating voltage of 220 V is applied across a device X, a current of 0.5 A flows

04:49

3. A current of 1 A flows through acoil when it is connected across a DC battery of 100 V

02:57

2. An alternating voltage V= 140 sin 314 t is connected across R=50 ohm. Find i. frequency ii. rms

01:56

1. An alternating current from a source is given by i=10 sin 314 t. What is the effective value of

01:16

10. The photoelectric cut-off voltage in a certain experiment is 1.5 V. What is the maximum

00:58

9. Obtain the expression for the maximum kinetic energy of the electrons emitted from a metal

01:12

8. It is difficult to remove a free electron from copper than from sodium? Why?

04:32

7. Light of wavelength falls on an aluminum surface. In aluminum 4.2 eV arerequired

00:37

6. Electron and proton are moving with same speed, which will have more wavelength?

01:17

5. Show graphically how the stopping potential for a given photosensitive surface varies with the

02:30

4. Calculate the threshold frequency of photon for photoelectric emission from a metal of

00:52

3.The maximum kinetic energy of photoelectron is 2.8 eV. What is the value of stopping potential?

00:29

2.Mention one physical process for the release of electron from the surface of a metal?

03:04

1.Calculate the energy associated in eV with a photon of wavelength 4000 A ?

04:30

15. A p-n photodiode is fabricated from a semiconductor with band gap of 2.8 eV. Can it detect a

01:58

14. Two semiconductor materials A and B shown in the figure are made by doping germanium crystal

01:15

13. In the following diagrams indicate which of the diodes are forward biased and which are reverse

05:22

12. With the help of a labeled circuit diagram, explain full wave rectification using junction diode

01:03

11. What is an ideal diode? Draw the output wave form across the load resistor R, if the input

00:43

10. 10. Why is a semiconductor damaged by a strong current?

01:26

9. Which type of biasing gives a semiconductor diode very high resistance?

00:38

8. Under what condition does a junction diode work as open switch?

00:49

7. How does width of depletion layer of p.n junction diode change with decrease in reverse bias?

02:11

6.How does the energy gap of an intrinsic semiconductor vary, when doped with a trivalent impurity?

00:58

5. A semiconductor has equal electron and hole concentration of 6*108 m3 . On doping with a certain

01:19

4.Draw an energy level diagram for an intrinsic semiconductor?

00:58

3.Doping of silicon with indium leads to which type of semiconductor?

00:41

2.What type of impurity is added to obtain n-type semiconductor?

00:53

1. Give the ratio of number of holes and the no. of conduction electrons in an intrins

00:30

11. Define solubility.

01:20

10. If 50 g of solute is dissolved in 450 g of solvent, calculate the concentration of the solution

02:07

9. A solution contains 25 g of sugar, 50 g of salt, and 75 g of urea in 350 g of water. Calculate

02:14

8. A solution is prepared by dissolving 40 g of glucose and 60 g of NaCl in 500 g of water.

01:11

7. A solution is prepared by dissolving 30 g of NaCl in 270 g of water. Calculate the

01:15

6. A saline solution contains 10 g of salt in 90 g of water. Calculate its mass percentage

01:35

5. A bottle contains 500 mL of fruit juice, in which 150 mL is the actual fruit extract. Find the

01:09

4. If 30 g of solute is dissolved in 120 mL of solution, calculate the mass by volume percentage.

02:15

3. A sugar solution is prepared by dissolving 25 g of sugar in 125 g of water. Calculate the

01:32

2. A solution is made by mixing 50 mL of ethanol with 200 mL of water. Find the volume by volume

01:18

1. A solution is prepared by dissolving 20 g of salt in 80 g of water.

00:59

8. Why chemical properties of all the isotopes of an element are same?

00:31

10. (iii) An element ‘X’ has 2 electrons in its M shell. What is its atomic number?

00:23

9. (ii) Name the isotopes used in the treatment of goitre and cancer.

00:44

7. The ion of an element has three positive charges

01:50

6. How do you find the valency of chlorine, sulphur and magnesium?

02:58

5. Hydrogen has three isotopes. State the composition of their nuclei and write their mass numbers.

01:05

4. There are 15 protons and 16 neutrons in the nucleus of an element. Calculate its atomic

01:42

3. There are two elements 26A13 and 26Al14. Find the number of sub-atomic particles i

00:47

Q2. Illustrate that Na atom has completely filled K and L shells.

01:25

1. How many electrons, protons and neutrons will be there in an element 9𝑿19? What will

03:51

38. Plantation drives are often carried out especially during monsoon season for the protection of

03:13

37. Ethanol (commonly known as alcohol) is an important carbon compound widely used in industries,

00:48

36 II B. Calculate the amount of heat produced in a conductor of resistance 10 Ὼ through which a

02:29

36 II A What is meant by heating effect of electric current ? Derive an expression for the amount

02:58

36 B. Find the electrical resistivity of the material of a wire of length 120 cm and diameter

01:30

36 A. Write the relation between resistance and electrical resistivity of the material of a

02:16

35 B. Study the diagram below showing schematic representation of transport and exchange of gases

02:23

35 A. (i) Study the diagram below of alimentary canal of man and name the parts marked as A, B and

03:23

34. Write electronic configurations of two elements X (At. no. 12) and Y (At. no. 17). Show the