Your cart is empty.
Practice each question, then open the answer or worked solution.
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.
Draw the circuit diagram to represent the circuit shown in Fig.14.21.
Fig.14.22 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.
The bulb in the circuit shown in Fig.14.23 does not glow. Can you identify the problem? Make necessary changes in the circuit to make the bulb glow.
In the circuit above, the bulb is connected on either side.
Name any two effects of electric current.
i) Heating effect of electric current
ii) Magnetic effect of electric current
When the current is switched on through a wire, a compass needle kept nearby gets deflected from its north-south position. Explain.
When the current is switched on through a wire, the magnetic field is created around it hence we see deflection in the compass needle kept nearby.
Will the compass needle show deflection when the switch in the circuit shown by Fig.14.24 is closed?
No, the compass needle does not show deflection when the circuit is closed, and the magnetic field is not created until the current is flowing through the circuit.
Fill in the blanks:
(a) Longer line in the symbol for a cell represents its ________ terminal.
(b) The combination of two or more cells is called a _________.
(c) When the current is switched ‘on’ in a room heater, it _______.
(d) The safety device based on the heating effect of electric current is called a ______.
(a) Longer line in the symbol for a cell represents its positive terminal.
(b) The combination of two or more cells is called a battery.
(c) When the current is switched ‘on’ in a room heater, it produces heat.
(d) The safety device based on the heating effect of electric current is called a fuse.
Mark ‘T’ if the statement is true and ‘F’ if it is false:
(a) To make a battery of two cells, the negative terminal of one cell is connected to the negative terminal of the other cell. (T/F)
(b) When the electric current through the fuse exceeds a certain limit, the fuse wire melts and breaks. (T/F)
(c) An electromagnet does not attract a piece of iron. (T/F)
(d) An electric bell has an electromagnet. (T/F)
a) False
b) True
c) False
d) True
Do you think an electromagnet can be used for separating plastic bags from a garbage heap? Explain.
No, because plastic does not have the magnetic property to get attracted to a magnet; hence magnet cannot be used to separate plastic bags.