English
Maharashtra State BoardSSC (English Medium) 10th Standard

State Four Most Common Electrical Appliances Based on Heating Effect of Electric Current. Why Do We Use Finely Heated Platinum Wire in Surgery?

Advertisements
Advertisements

Question

State four most common electrical appliances based on heating effect of electric current. Why do we use finely heated platinum wire in surgery?

Advertisements

Solution

The four most common appliances based on the heating effect of electrical current are electric iron, electric heater, electric oven and electric toaster. Finely heated platinum wire is used in surgery for cutting tissues much more efficiently than a knife.

shaalaa.com
  Is there an error in this question or solution?
2014-2015 (March)

APPEARS IN

RELATED QUESTIONS

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


Why is the tungsten used almost exclusively for filament of electric lamps?


Why are the conductors of electric heating devices, such as bread-toasters and electric irons, made of an alloy rather than a pure metal?


Name any two effects of electric current.


When current is switched ‘on’ in a room heater, it ______.


The safety device based on the heating effect of electric current is called a ______.


How does the resistance of a wire vary with its: 

 diameter? 

 


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


Explain why, tungsten is used for making the filaments of electric bulbs.


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


The current passing through an electric kettle has been doubled. The heat produced will become:

(a) half
(b) double
(c) four time
(d) one-fourth 


The electrical resistivities of four materials P, Q, R and S are given below:

P `6.84xx10^8`Ωm
Q `1.70xx10^8`Ωm  
R ` 1.0xx10^15`Ωm
s  `11.0xx10^-7`Ωm  

Which material will you use for making: (a) heating element of electric iron (b) connecting wires of electric iron (c) covering of connecting wires? Give reason for your choice in each case.

 


Give a scientific reason.

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


Give a scientific reason:

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


Why does tungsten metal used to make solenoid type coil in an electric bulb?


The ‘live’ and the ‘neutral’ wires have potential difference of _______.


Find the odd one out and give its explanation.


Live wire and neutral wires have a 220 V potential difference.


Name any two appliances which works on the phenomenon of heating effect of electric current.


Explain the heating effect of electric current.


An electric iron consumes energy at the rate of 420 W when heating is at the maximum rate and 180 W when heating is at the minimum rate. The applied voltage is 220 V. What is the current in each case?


An electric iron draws a current of 4 A when connected to 220 V mains. Its resistance must be:


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.

Unscramble the following words:

SFEU


Name two electric devices for each where

  1. heating effect of current is used and
  2. magnetic effect of current is used.

Assertion: A current-carrying wire should be charged.
Reason: The current in a wire is due to the flow of free electrons in a definite direction.


A student boils water in an electric kettle for 20 minutes. Using the same mains supply he wants to reduce the boiling time of water. To do so should he increase or decrease the length of the heating element? Justify your answer.


What is a trip switch?


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


An electric kettle of 2 kW is used for 2h. Calculate the energy consumed in 

  1. kilowatt hour and
  2. joules.

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?


An electric iron is rated 220 V, 2 kW. If the iron is used for 3h daily find the cost of running it for one week if it costs ₹ 4.25 per kWh.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×