Electric Current and its Effect - Chapter Wise CBSE Solved Question and Answer Based On NCERT
Very Short Q&A:
Q1: Circuit diagram is a simplified conventional pictorial representation of an_______________.
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electrical circuit
Q2: A circuit diagram uses standard symbols for electric components. True/ False.
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True.
Q3: Define electric circuit.
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A closed path formed by the interconnection of electrical components through which electric current flows is called an electrical circuit.
Q4: For a bulb to glow, it must be connected to a battery. Why?
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because a bulb will require more power
Q5: What is a cell holder?
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A compartment that holds two or more cells together to form a battery is called a cell holder.
Q6: If current does not flow through a circuit, then it is said to be an
Open circuit
Closed circuit
Incomplete circuit
Both a and c
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Both a and c
Q7: A circuit is said to be open circuit or complete when current flows through it.. True/ False.
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False
Q8: What is a battery?
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A combination of two or more cells connected together is called a battery. It is formed by connecting the positive terminal of one cell to the negative terminal of another.
Q9: The symbol for battery is
a.
b.
c.
d. None of these
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c.
Q10: Draw the symbol for electric bulb in an electric circuit.
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Q11: Which one of the two minimise wastage of electricity CFL’s or an electric bulb?
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CFL’s
Q12: Enlist some appliances that work on the property of the heating effect of electric current.
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the electric room heater, electric roti maker, electric iron, toaster, hair dryer, electric stove, immersion water heater, food warmer, electric coffee maker, electric rice cooker and geyser.
Q13: Electric room heaters have coils of wire that produce heat, which are known as heating elements.True/False.
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True
Q14: State some factors that affect production of heat in a wire through which an electric current is passing.
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Length and thickness of the wire, the duration of flow of current, and the material of the wire.
Q15: Name the principle of working of electric fuse.
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The electric fuse works on the principle of the heating effect of electric current.
Q16: What is an electric fuse?
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An electric fuse is a safety device to prevent damage to an electrical circuit when excessive current flows through it.
Q17: What is the full form of MCB?
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Multiple Circuit Breakers
Q18: What is the full form of CFL’s?
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Compact Fluorescent Lamps
Q19: State one advantage of MCB.
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These switches turn off automatically when there is an overload or a short circuit.
Q20: An electromagnet does not attract a piece of iron.
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False
Q21: When current is switched ‘on’ in a room heater, it_________________.
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gives out heat
Q22: Longer line in the symbol for a cell represents its ------- terminal.
Negative
Positive
Neutral
None of these
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Negative
Q23: Name a safety device in domestic circuit used to prevent electrical fire due to short circuit or overloading.
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Electric fuse.
Q24: Enlist some appliances that work on the property of the magnetic effect of electric current.
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Electric Bell, Motor, Fan etc.
Q25: What is meant by electric current?
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Electric Current: Flow of electrons.
Q26: What is an electric circuit?
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Electric Circuit : The closed path in which electric current flows
Q27: What happens when current is switched ‘on’ in a room heater?
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It becomes red hot and gives out heat
Q28: Which of the two absorbs more radiation- a dark coloured object or a light coloured object?
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Heating effect of electric current and magnetic effect of electric current.
Q29: Would any of the bulbs glow when the switch is in the ‘OFF’ position in a circuit?
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None of the bulb will glow when the switch is in the ‘OFF’ position as there will be no electric current in the circuit.
Q30: What is a circuit diagram?
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In an electrical Circuit when we replace electrical components with their symbols we call it Circuit diagram.
Q31: When the electric current through the fuse exceeds a certain limit, the fuse wire melts and breaks. True/False
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True
Q32: The combination of two or more cells is called a __________________.
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Battery
Q33: A straight wire carrying electric current is moving out of plane of paper and is perpendicular to it. What is the direction and type of induced magnetic field?
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Induced magnetic field will be in the form of concentric circles in the plane of paper.
Q34: A current through a horizontal power line flows in north to south direction.What is the direction of magnetic field (i)at a point directly below it and (ii)at a point directly above it?
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(i) West to East (ii) East to West
Q35: What do you mean by electromagnetic induction?
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The process, due to which a changing magnetic field in a conductor induces a current in another conductor, is called electromagnetic induction.
Q36: How we can show that magnetic field exist around a wire carrying current?
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By using magnetic compass which, shows deflection.
Q37: How can a solenoid be used to magnetise a steel bar?
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By inserting the steel bar inside the solenoid and switching on electric current.
Q38: Give the factors that affect strength of magnetic field at a point due to a straight conductor carrying current.
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Magnitude of electric current, perpendicular distance between that point and conductor.
Q39: A fuse is connected with a live wire or with neutral wire?
