CBSE NCERT Class VII (7th) | Science

Chapter 14  :  Electric Current and Its Effects


CBSE NCERT Solved Question Answer


Question: 1 - Draw in your notebook the symbols to represent the following components of electrical circuits: connecting wires, switch in the ‘OFF’ position, bulb, cell, switch in the ‘ON’ position, and battery.
Answer:
Get to know about Electric Current and Its Effects (Ncert / Cbse Solutions & Revision Notes), Chapter Summary\, CBSE / NCERT Revision Notes, CBSE NCERT Class VI (7th) | Science, CBSE NCERT Solved Question Answer, CBSE NCERT Solution.


Question: 2 - Draw the circuit diagram to represent the circuit shown in the following figure.
Get to know about Electric Current and Its Effects (Ncert / Cbse Solutions & Revision Notes), Chapter Summary\, CBSE / NCERT Revision Notes, CBSE NCERT Class VI (7th) | Science, CBSE NCERT Solved Question Answer, CBSE NCERT Solution.

Answer:

Get to know about Electric Current and Its Effects (Ncert / Cbse Solutions & Revision Notes), Chapter Summary\, CBSE / NCERT Revision Notes, CBSE NCERT Class VI (7th) | Science, CBSE NCERT Solved Question Answer, CBSE NCERT Solution.

Question: 3 - The following figure shows four cells fixed on a board. Draw lines to indicate how you will connect their terminals with wires to make a battery of four cells.

Get to know about Electric Current and Its Effects (Ncert / Cbse Solutions & Revision Notes), Chapter Summary\, CBSE / NCERT Revision Notes, CBSE NCERT Class VI (7th) | Science, CBSE NCERT Solved Question Answer, CBSE NCERT Solution.

Answer:

Get to know about Electric Current and Its Effects (Ncert / Cbse Solutions & Revision Notes), Chapter Summary\, CBSE / NCERT Revision Notes, CBSE NCERT Class VI (7th) | Science, CBSE NCERT Solved Question Answer, CBSE NCERT Solution.

Question: 4 - The bulb in the circuit shown in the following figure does not glow. Can you identify the problem? Make necessary changes in the circuit to make the bulb glow.

Get to know about Electric Current and Its Effects (Ncert / Cbse Solutions & Revision Notes), Chapter Summary\, CBSE / NCERT Revision Notes, CBSE NCERT Class VI (7th) | Science, CBSE NCERT Solved Question Answer, CBSE NCERT Solution.

Answer: The positive terminals of both the cells are together and that is why the bulb is not glowing. The cells should be kept in a way that the positive terminal of one cell is near the negative terminal of another cell; to make the bulb glow.

Question: 5 - Name any two effects of electric current.
Answer: The two effects of electric current are; heating effect and magnetic effect.

Question: 6 - When the current is switched on through a wire, a compass needle kept nearby gets deflected from its north-south position. Explain.
Answer: This happens because when electric current passes through a conducting wire, a magnetic field is created around the wire. The magnetic field causes deflection in the magnetic compass.

Question: 7 - Will the compass needle show deflection when the switch in the circuit shown by following figure is closed?
Get to know about Electric Current and Its Effects (Ncert / Cbse Solutions & Revision Notes), Chapter Summary\, CBSE / NCERT Revision Notes, CBSE NCERT Class VI (7th) | Science, CBSE NCERT Solved Question Answer, CBSE NCERT Solution.
Answer: Yes

Question: 8 - Fill in the blanks:
  1. Longer line in the symbol for a cell represents its …………..terminal.

    Answer: Positive
  2. The combination of two or more cells is called a ……………

    Answer: Battery
  3. When current is switched ‘on’ in a room heater, it ……………….

    Answer: heats up
  4. The safety device based on the heating effect of electric current is called a ……………

    Answer: Electric fuse

Question: 9 - Mark ‘T’ if the statement is true and ‘F’ if it is false:
  1. To make a battery of two cells, the negative terminal of one cell is connected to the negative terminal of the other cell. (F)
  2. When the electric current through the fuse exceeds a certain limit, the fuse wire melts and breaks. (T)
  3. An electromagnet does not attract a piece of iron. (F)
  4. An electric bell has an electromagnet. (T)

Question: 10 - Do you think an electromagnet can be used for separating plastic bags from a garbage heap? Explain.
Answer: Since plastic is a non-magnetic material, so electromagnet cannot be used to separate plastic bags from a garbage heap.

Question: 11 - An electrician is carrying out some repairs in your house. He wants to replace a fuse by a piece of wire. Would you agree? Give reasons for your response.
Answer: A special wire with low melting point should be used for the fuse wire and any other wire would not serve the purpose. Hence, I would not agree with the electrician.

Question: 12 - Zubeda made an electric circuit using a cell holder shown in Fig. 14.4 (in the chapter), a switch and a bulb. When she put the switch in the ‘ON’ position, the bulb did not glow. Help Zubeda in identifying the possible defects in the circuit.
Answer: There can following possibilities:
  • The terminals of cells are not in correct position.
  • The connections are loose.
  • The bulb may have fused.
Question: 13 -In the circuit shown in the following figure:

Get to know about Electric Current and Its Effects (Ncert / Cbse Solutions & Revision Notes), Chapter Summary\, CBSE / NCERT Revision Notes, CBSE NCERT Class VI (7th) | Science, CBSE NCERT Solved Question Answer, CBSE NCERT Solution.

  1. Would any of the bulb glow when the switch is in the ‘OFF’ position?

    Answer: None of the bulbs would glow.
  2. What will be the order in which the bulbs A, B and C will glow when the switch is moved to the ‘ON’ position?

    Answer: All the bulbs would glow at once.

Chapter Summary : Electric Current and Its Effects
        ·          Electric Components
        ·         The Heating Effect of Electric Current

        ·         The Magnetic Effect of Electric Current

Post a Comment Blogger

 
Top