मराठी

Name two electric devices for each where heating effect of current is used and magnetic effect of current is used.

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प्रश्न

Name two electric devices for each where

  1. heating effect of current is used and
  2. magnetic effect of current is used.
अति संक्षिप्त उत्तर
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उत्तर

  1. Current heating devices are used room heaters and geysers.
  2. Cranes and electric bells employ the magnetic influence of current.
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  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 14: Electric Current and Its Effects - SHORT ANSWER QUESTIONS [पृष्ठ ७८]

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एनसीईआरटी एक्झांप्लर Science [English] Class 7
पाठ 14 Electric Current and Its Effects
SHORT ANSWER QUESTIONS | Q 14. | पृष्ठ ७८

संबंधित प्रश्‍न

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?


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


Give Scientific reason.

In practice, the unit kWh is used for the measurement of electrical energy, rather than joule.


Statement 1 : Electric current ( flow of electrons ) creates heat in the resistor.
Statement 2 : Heat in the resistor is created according to the rule of energy conservation.
Explain Statement 1 with the help of Statement 2.


The electricity bill specifies the usage in _______.


Which of the following substance contracts on heating?


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 OFF position,

  1. circuit starting from the positive terminal of the cell stops at the switch.
  2. circuit is open.
  3. no current flows through it.
  4. current flows after some time. 

Choose the combination of correct answer from the following.


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

A B C D

In a set up the students coated iron nails with zinc metal and noted that, iron nails coated with zinc prevents rusting. They also observed that zinc initially acts as a physical barrier, but an extra advantage of using zinc is that it continues to prevent rusting even if the layer of zinc is damaged. Name this process of rust prevention and give any two other methods to prevent rusting.


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