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महाराष्ट्र राज्य शिक्षण मंडळएस.एस.सी (इंग्रजी माध्यम) इयत्ता १० वी

Which of the following substance contracts on heating? - Science and Technology 1

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प्रश्न

Which of the following substance contracts on heating?

पर्याय

  • Lukewarm water

  • Ice

  • Iron

  • Mercury

MCQ

उत्तर

Ice

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  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 4: Effects of electric current - Choose the correct option.

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संबंधित प्रश्‍न

An electric heater of resistance 8 Ω draws 15 A from the service mains 2 hours. Calculate the rate at which heat is developed in the heater.


How does the resistance of a wire vary with its area of cross-section?


Write Joule's law of heating.


An electric heater is connected to the 230 V mains supply. A current of 8 A flows through the heater. 

(a) How much charge flows around the circuit each second?


An electric room heater draws a current of 2.4 A from the 120 V supply line. What current will this room heater draw when connected to 240 V supply line?


How does the resistance of a wire vary with its: 

 diameter? 

 


Why does the connecting cord of an electric heater not glow hot while the heating element does?


Write down the formula for the heat produced when a current I is passed through a resistor R for time t.


A resistance of 25 Ω is connected to a 12 V battery. Calculate the heat energy in joules generated per minute.


Derive the expression for the heat produced due to a current 'I' flowing for a time interval 't' through a resistor 'R' having a potential difference 'V' across its ends. With which name is this relation known?


 How much heat will an instrument of 12 W produce in one minute if it is connected to the heat produced by it?  


What is meant by the heating effect of current? Give two applications of the heating effect of current. 


The heat produced in a wire of resistance 'x' when a current 'y' flows through it in time 'z' is given by:

(a) x2 × y × z
(bx × z × y2
(cy × z2 × x
(dy × z × 


Give a scientific reason.

Tungsten metal is used to make a solenoid type coil in an electric bulb.


Give Scientific reason
In the electric equipment producing heat e.g. iron, electric heater, boiler, toaster etc, an alloy such as Nichrome is used, not pure metals.


Give a scientific reason.

For electric power transmission, copper or aluminium wire is used.


Identify the figure and give its use.


Name the factors on which the heat produced in a wire depends when current is passed in it, and state how does it depend on the factors stated by you.


Solve the following question.
Compute the heat generated while transferring 96000 coulombs of charge in two hours through a potential difference of 40 V.


A coil of an alloy _______ is used in electric heater cooker as a resistor.


How can overloading be avoided?


Heating effect of current is called ______


A fuse wire repeatedly gets burnt when used with a good heater. It is advised to use a fuse wire of:


The heating element of an electric iron is made up of:


An electric bulb is connected to a 220 V generator. The current is 0.50 A. What is the power of the bulb?


Assertion: Bending of wire decreases the resistance of the electric wire.

Reason: The resistance of a conductor depends on length, thickness, nature of material and temperature of the conductor.


An electric kettle consumes 1 kW of electric power when operated at 220 V. A fuse wire of what rating must be used for it?


Three incandescent bulbs of 100 W each are connected in series in an electric circuit. In another circuit another set of three bulbs of the same wattage are connected in parallel to the same source.

  1. Will the bulb in the two circuits glow with the same brightness? Justify your answer.
  2. Now let one bulb in both the circuits get fused. Will the rest of the bulbs continue to glow in each circuit? Give reason.

When a switch is in the OFF position,

(i) circuit starting from the positive terminal of the cell stops at the switch.

(ii) circuit is open.

(iii) no current flows through it.

(iv) current flows after some time. Choose the combination of the correct answers from the following.


An MCB can be used instead of a fuse in an electrical circuit.


Match the following

1. Bulb a. Conductor
2. Electroplating b.

Insulator

3. Pure water c.  Heating effect of current
4. Salt solution d. Chemical effect of current

Name a few appliances which work on the basis of the heating effect of current.


What is a trip switch?


An electric fuse is a wire made up of a material having ______ melting point.


In the electric equipment producing heat like iron, electric heater, boiler, toaster etc., an alloy such as nichrome is used, not pure metals.


In which of the following applications of Iron, rusting will occur most? Support your answer with valid reason.

A B C D

When a current I flows through a wire of resistance R for time t then the electrical energy produced is given by ______.


The graph of voltage vs current for four different materials is shown below.

Which of these four materials would be used for making filament of bulb?


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