Read the following and answer the questions:
In resistance for a system of the resistor, there are two methods of joining the resistors together as shown below.It showed an electric current in which 3 resistors having resistor R1 ,R2 and R3 respectively are join end to end i.e series. While the combination of the resistor in which 3 resistors connected together which point X and Y are said to be parallel.
1.Find the least count of the following voltmeter.
2.Three 2 V cells are connected in series and used as a battery in a circuit.
(a) What is the p.d. at the terminals of the battery ?
(b) How many joules of electrical energy does 1 C gain on passing through (i) one cell (ii) all three cells ?
3. The resistance of a wire of 0.01 cm radius is 10 Ω. If the resistivity of the material of the wire is 50 × 10–8 ohm metre, find the length of the wire.
4.A charge of 150 coulomb flows through a wire in one minute. Find the electric current flowing through it.
5. A voltmeter is to be connected in the circuit to measure potential difference
across a conductor. Mention the type of combination in which it should be connected with the conductor.
6.What is the shape of the graph between V and I, where V is the potential difference applied between the ends of a wire and I is the current flowing through it?
7. Three resistors of 10 Ω, 15 Ω and 5 Ω are connected in parallel. Find their equivalent resistance?
Answers
Answer:
So far, you have read about various factors which affect electric current. You also read about the factors which affect the resistance of a conducting wire. In these sections, we discussed simple circuits. But in practical situations, many resistors are used in combination. For example; the wiring of a room may contain various resistors in different combinations. In this section, you will read about different possible combinations of resistors.Resistors are combined in two types of combination, viz. series combination and parallel combination. The following figure shows the series combination of resistors. In this circuit, R1, R2 and R3 are the three resistors which are in series combination. When resistors are connected end to end, i.e. one terminal of one resistor is connected to the terminal of the next resistor and so on, this is called series combination.
The following figure shows the parallel combination of resistors. In this circuit, R1, R2 and R3 are the three resistors which are in parallel combination. When one terminal of all resistors are connected together and another terminal is also connected in the same way, it is called parallel combination.
1. Find Least count of Ammeter and Voltmeter given below
Voltmeter Ammeter
For Voltmeter, We see that 10 Divisions is equal to 5 Volts So, Least Count = 5/10 = 0.5 V For Ammeter, We see that 10 Divisions is equal to 100 Milli Amperes So, Least Count = 100/10 mA = 10 mA = 10 × 10 -3 A = 10 -2 A = 0.01 A
2. If three cells of 2 volt each are connected in series to make a battery, then the total potential difference between terminals of the battery will be 6V
a) The potential difference across the battery is 9 volts when a current of 2A
b) flows within it from its negative to its positive terminal
for all three cells the given pd is 2 The answer is 6 joules because for all three cells the given pd is 2 multiply by all three cells the answer is 6 joules
3. The resistance of a wire of 0.01 cm radius is 10 Ω. If the resistivity of the material of the wire is 50 × 10⁻⁸ ohm meter, find the length of the wire. ⇒ l = 0.628 m. Hence, the length of the wire is 0.628 m
4. Charge Q = 150 coulombTime t = 1 minute = 60 sec. Current I = ? I=Q/t=150/60=2.5 Amp.
5. A voltmeter is a device which must always be connected in parallel combination in relation to the conductor . Voltmeter measures the potential difference between two points and connecting it in series gives it no two points to calculate voltage between
6. what is the shape of the graph between V and i where V is the potential difference between the ends of a wire and i is the current in it. The graph will be a straight line. Aakash EduTech Pvt. Ltd.
7. Here it is given that
R1 = 10 Ω
R2 = 15 Ω
R3 = 5 Ω
R1, R2 and R3 are connected in parallel, then equivalent resistance R is given by
1/R = 1/R1 + 1/R2 + 1/R3
1/R = 1/10 + 1/15 + 1/5
1/R = 11/30
So R = 30/11
Therefore Equivalent resistance, R = 30/11 = 2.72 Ω
Hope it'll help uh!
Answer:
Q17. In resistance for a system of the resistor, there are two methods of joining the resistors together as shown below. P 1 It showed an electric current in which 3 resistors having resistor R 1 ,R 2 and R 3 respectively are join end to end i.e series. While the combination of which 3 resistors connected together which point X and Y are said to be parallel. the resistor in i) The total potential difference across a combination of a resistor in series is equal to a) V 1 +V 2 +V 3 b) V 1 +V 1 b) V 1 -V 2 +V 2 d)None of these ii) In a series combination of resistor, the current is a) same at every point of the circuit b) different at every point of the circuit b) zero d) cannot be determined i) The electrical energy dissipated in the resistor is given by a) W = VTT c) W = RTT b) W = VIR d) W = RT iv) If 5 resistor, each of value 0.2 2 are connected in series what will be the resultant resistance a) 10 b) 1/25 * Omega b) 102 d) 252