ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

quiz Chem_Phy

Updated on October 17, 2017

Phys_Puzzle

A voltmeter is to be connected in the circuit to measure potential difference across a conductor. Mention the type of combination in which it should be connected with the conductor.

Answer- In parallel.

Name two constituents of biogas; one should be the chief constituent.

Answer- Methane – Chief , Carbon dioxide, hydrogen, hydrogen sulphide (Any one)

What is the minimum speed of wind to run a windmill to maintain the necessary speed of turbine of an electric generator?

Answer- 15Km/h

How is the nuclear energy generated during nuclear fusion?

Answer-In nuclear fusion, the difference in mass, between the original nucleus (2 deuterons) and a product nuclei (helium) gets converted to energy as per Einstein’s mass energy equation i.e. E=Δm.c2.

How has the traditional use of wind energy been modified for our convenience?

Answer-With the help of wind energy, rotatory motion of windmill is utilised to: 1. Lift water from a well 2. Turn the turbine off electric generator that generates.

With the help of a diagram for the experimental setup describe an activity to show that a current carrying conductor placed in a uniform magnetic field experiences a force.

Answer-

Diagram (fig 13.12, p 230) NCERT-BOOK

when plug is inserted the conductor moves towards the left. When current or field direction is reversed it moves towards the right.

“The magnetic field produced at its centre by a coil of n turns is n times as large as produced by a single turn”. Give reason to justify this statement.

Answer-

  • · Strength of magnetic field depends directly on the strength of current.
  • · Current in every turns is in the same direction.
  • · so the fields add up

Ravi was using calculator to do some calculations. While doing so his calculator stopped working. He kept the calculator near the window for some time, exposed to sunlight. After some time he could use the calculator again. His friend Mohit who was using a battery operated calculator, watched him and told him that his calculator was better in the sense that he could immediately recharge the calculator by charging battery but Ravi was not convinced. He explained to Mohit the advantages of solar calculator and convinced him to adopt it.

(a) State the values exhibited by Ravi.

(b) List the advantages of using a calculator driven by solar energy which

convinced Mohit too to adopt it.

Answer-

(a) Ravi has concern for conservation of energy resources and environment. He wants that his friends too should be equally aware of these concerns.

(b) Solar energy is renewable.

It does not cause pollution.

If energy can neither be created nor destroyed, explain with an example as to why we should worry about our energy resources?

Answer- Energy used is dissipated in less usable form

The energy used is consumed and cannot be used again

Example : Burning of candle light + heat but products cannot produce chemical energy (or any other example)

The flow of current in a circular loop of wire creates a magnetic field at its centre. How can the existence of this field be detected? State the rule which helps to determine the direction of this magnetic field.

Name four common devices that use current carrying conductors and magnetic fields.

Answer- Activity 13.6 Fig. 13.9 Page 229 NCERT book.

The direction of field is given by right hand rule. For statement Fleming‘s right hand rule refer page 235 Fig 13.18

Four devices: Electric motor, electric generator, loud speaker, microphone, galvanometer, television, computer, electronic camera. etc (any four)

State Ohm’s law. Write the necessary condition for its validity. How is this law verified experimentally? What will be the nature of graph between potential difference and current for a conductor? Name the physical quantity that can be determined from this graph.

Answer-

● Statement of Ohm’s law

● Necessary condition – No change in physical condition and temperature

● Brief description of verification

● Straight line graph passing through origin

● Resistance of the conductor/ resistor

How many 40 W; 220 V lamps can be safely connected to a 220 V, 5 A line? Justify your answer.

Answer-

(i)The fuel used in thermal power plant is coal, so it may create air pollution which may lead to the global warming. Whereas in the use of solar panels, it is pollution free and free of cost.

(ii)awareness of global issues, caring, loving nature or any other

Rahim, a student of class X lives in Delhi. He had an idea in his mind of setting up a thermal power plant in the nearby village. His friend Rohan suggested him to set up a solar cell panel to harness solar energy instead of a thermal power plant.

Answer the following questions :

(i) Do you think that Rohan’s suggestion was appropriate? Justify your answer.

(ii) Mention the quality of Rohan portrayed in his act.

List any three parameters, which categories any source of energy as a good source of energy?

Answer-

• Does average amount of work per unit volume or mass

• easy to store and transport

• easily accessible

• be economical

Any three

A student fixes a sheet of white paper on a drawing board. He places a bar magnet in the centre of it. He sprinkles some iron filings uniformly around the bar magnet. Then he taps the board gently.

Now answer the following questions :

(i) What does the student observe ? Draw a diagram to illustrate your answer.

(ii) Why do the iron filings arrange in such a pattern ?

(iii) What does the crowding of the iron filings at the ends of the magnet indicate ?

Answer-

(i) Student observes that iron filings arrange in a definite pattern around the magnet.

For fig refer Page 224 Fig 13.2 NCERT Text book.

(ii) The magnet exerts its influence in the region surrounding it. Therefore, the iron

filings experience a force and get arranged in such a pattern.

(iii)The crowding of the iron filings at the ends (poles) of the magnet indicates that

magnetic filed is strongest at the poles.

Chem_Puzzle

Rohit added small amount of common salt to water taken in a graduated cylinder, on dissolution there was no detectable change in the level of water. Explain why is it so?

Which technique crystallization or evaporation is better to obtain salt from sea water?

We cannot cut a stream of water with our finger. Which characteristic of particles of matter do you infer from this activity?

What is dry ice?

Which technique crystallization or evaporation is better to obtain salt from sea water?

Anita tested the solubility of four salts A, B, C and D at different temperatures and collected the following data (solubility means amount of solute grams dissolved in 100g of water to give a saturated solution).

Salt dissolved Solubility at different temperatures

158C 408C 508C 608C 708C

A 23 35 40 92 105

B 44 44 46 50 50

C 25 30 34 37 40

D 24 38 40 54 65

Study the data and answer the following questions :

(i) Which salt has the highest solubility and lowest solubility at 508C?

(ii)The solubility of which salt is least affected by an increase in temperature?

(iii)Which salt shows considerable increase in solubility with increasing temperature?

Explain why a diver is able to cut through water in a swimming pool.

Give reasons why:

a. Water should be called a liquid.

b. We can smell the food being cooked in the kitchen all over the room.

c. Clothes dry faster on a windy day.

A container contains two miscible liquids A and B. They have a difference of 40 degree Celsius in their boiling points. How will you separate these liquids?

A blue dye is made up of several pigments of shades of blue. Which technique can help separate the different colored dyes?

Give reasons for the following :

(a)After rains wet roads dry quickly.

(b)We prefer to wear cotton clothes during summer.

(c)Trees acquire more leaves during summer.

(d)On pouring acetone on our palm we feel cool.

(e)People sprinkle water on his roof on a hot summer day.

Comments

    0 of 8192 characters used
    Post Comment

    No comments yet.