Kerala Syllabus SAMAGRA SCERT SAMAGRA Question Pool for Class 9 English Medium Physics Current Electricity
Q is the midpoint of the resistor AB. If 4A current flowed through the resistor when the switch was turned on as shown in the figure, then
a)If the point S touches the midpoint Q of AB, what will be the current in the circuit?
b)In the same circuit, if the point A is connected to the point B and S touches the midpoint Q of AB, then what will change the current?
c)If the conductor AB is stretched and doubled in length, will the current in the circuit be changed?
d) Explain your answer
a) When V / I = R; V / R = I
when S touches the midpoint Q, R is reduced by half, V / R / 2 = I; V / R = 2I The electric current doubles I = 8A
b)
Identify the relation in the first pair and complete the second pair
Current is formed in conductors ; By the flow of free electrons
Current is formed in electrolytes and gases; ...................................
By the flow of
Which among the following doesn’t influence the resistance of a conductors
(length, Area of cross section , density, resistivity)
.A table related to the resistance of a conductor is given. Complete the table
a- 20ohm
b-5 ohm
c-10
.Instrument used to regulate the current in a circuit by gradually changing the resistance is ------
Some symbols are given in the column A. Find out the suitable names from column B for each one and write against it.
IMAGE
a. cell b- Resistance, c-Bulb, d- Switch , e-
The resistance of a bulb is 42Ω. The current passed through the conductor when 230 V supplied is given in the table.
Complete the table
b) Will the resistance of the filament be same when the bulb is on and off? What could be the reason?
a) R=522.7Ω
b) No. When temperature increases the resistance also
Find out the relation from the first pair and complete the second pair
kgm/s^{2} : N
Volt/ Ampere : .............
Ohm
0.2 A current is flowing through a soldering iron having resistance 500Ω .Find out the voltage between the ends of the soldering iron.
According to Ohms law,V = IxR
= 500x0.2=
10A current is flowing through a heater working in 230V. Calculate the resistance of the heating coil.
According to Ohms Law V/I=R
20 coulomb charge passed in 5 seconds through a circuit when connected to a 12 volt battery.
a) What is the intensity of current through the circuit?
b) Which instrument is used to measure the Intensity of current?
c)Draw a circuit by including thid device.
Find the relation from the first pair and complete the second pair
Potential difference : Voltmeter
Intensity of current : ...............................
Find the relation from the first pair and complete the second pair
Potential difference : Volt (V)
Intensity of current : ...................
Calculate the intensity of current if a charge of 40 coulomb passes through a circuit in 8 seconds.
I =40/8=
Draw a circuit to get an effective voltage of 3V using 4 cells of each 1.5 volt.
Observe the circuit diagram given below and answer the questions.
IMAGE
a) How are the voltmeter and bulb connected in the circuit?
(series/parallel)
b) How will you connect an ammeter in the circuit to measure the current?
a) parallel
b) series
Cells connected in two different ways are shown below.
IMAGE
a) Find out and write how cells are connected in each circuit.
b) what change will happen to the effective voltage in the two arrangements?
a) series ,
b) parallel
b)
identify the relation from the first pair and complete the second pair
Generator ; Mechanical energy---- Electrical energy
Cell : ............................ ..........................
Chemical energy .... electrical
Which among the following are not a source of emf.
( Generator, Electric heater , solar cell, electro chemical cell, Electric motor)
Electric heater, Electric
if 10J work is done while moving 1 coloumb charge from P to Q ,what is the potential between the points
10V