Class 7 Science

Electric Current

NCERT Solution

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.


symbols in electric circuit

Question 2: Draw the circuit diagram to represent the circuit shown in figure. (See textbook for question figure)


electric circuit

Question 3: The given figure (in textbook) 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.


cells in electric circuit

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

bulb in electric circuit

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 in this figure is closed?

compass in electric circuit

Answer: Yes