These numerical problems from Ohm’s law topic are apt for class 9 physics and class 10 physics courses offered by boards like CBSE, ICSE.
Ohm’s law sample problems for CBSE, ICSE class 9 and class 10 physics
1> A cell is connected to a bulb which develops a potential difference of 24 volt across it. The current in circuit is measured to be 4 A. Find the resistance offered by the filament of the bulb to the flow of the current.
2> Calculate the potential difference across the ends of a wire of resistance 1 ohm when a current of 3 A passes through it.
3> Calculate the current flowing through a wire of resistance 15 ohm connected to a battery of potential difference 3 volt.
4> A cell of potential difference 12 V is connected to a bulb. The resistance of the filament of the bulb when it glows is 24 ohm. Find the current drawn from the cell.
5> A bulb draws current 1.5 A at 6 V. Find the resistance of filament of bulb while glowing?
6> A current 0.2 A flows in a wire of resistance 15 ohm. Find the potential difference across the ends of the wire.
7> When a 24 V battery is connected to a resistor, the current in it is 0.4 A. What is the resistance of the resistor? What would be the current through it when it is connected to a battery of 6 V?
We are coming up with more numerical problems(harder) on Ohm’s law in the 2nd set. (see below)
Ohm’s law problems – set 2
8> R1 = 10 ohm and R2 = 5 ohm in the diagram. Cell voltage is 7.5 V
Find out (a)the equivalent resistance (b) the electric current (c) the potential difference across each resistor in the circuit shown in figure (1).
9> Two resistances of 6 ohm and 12 ohm are connected in parallel. Calculate the equivalent resistance.
10> On 1 ohm resistor is connected in parallel to a 11 ohm resistor. What is equivalent resistance?
11> Two resistors of resistances R1 =10 ohm and R2= 20 ohm are connected in parallel. A battery supplies 6 A of current to this resistance combination as shown in figure 2. Calculate the current in each resistor.
12> A uniform wire of resistance R is cut into two equal pieces, and these pieces are joined in parallel. What is the resistance of the combination?
13> How will you join the resistors of resistances 3 ohm, 6 ohm and 8 ohm to get an equivalent resistance of 10 ohm?
14> 3 resistors, each of resistance 12 ohm, are connected in parallel. What is the equivalent resistance?
Law of Ohm – problem set 3
15> In the following circuit, R1 = 15 ohm and R2=30 ohm. The battery provides 6 V between A and B points. Find out the following:
(a) The equivalent resistance (b)The current passing the cell and, (c) the current passing through the 30 ohm resistor in the circuit shown above.
16> R1 = 20 ohm and R2 = 15 ohm in the circuit shown in figure 4 below.
The battery cell provides 7 V.
Find the current through the circuit. Also find the potential difference across the 20 ohm resistor.
17> A metal wire of resistance 6 ohm is stretched so that its length is increased to twice its original length. Calculate its new resistance.
18> How is the resistance of a wire affected if its (a) length is doubled. (b) radius is doubled? (c) length and radius both are doubled
19> What is the current in milliamperes produced by the solar cells of a pocket calculator through which 5.00 C of charge passes in 5.00 h?
20> A total of 1200 C of charge passes through a flashlight in 1 h. What is the average current?
21> What is the current when a typical static charge of 0.125 μC moves from your finger to a metal doorknob in 0.5 μs ?
22>Find the current when 2.00 nC jumps between your comb and hair over a 0.500 – μs time interval.
23> A large lightning bolt had a 20,000-A current and moved 30.0 C of charge. What was its duration?
24>The 200-A current through a spark plug moves 0.300 mC of charge. How long does the spark last?
** 101 Numericals with solutions for most
Physics problems (Laws of motion, gravitation, force, etc) for High School