Advertisements
Advertisements
Question
A battery of e.m.f 16 V and internal resistance 2 Ω is connected to two resistors 3Ω and 6Ω connected in parallel. Find:
- the current through the battery.
- p.d. between the terminals of the battery,
- the current in 3 Ω resistors,
- the current in 6 Ω resistor.
Advertisements
Solution
E.m.f. of battery E = 16V, r = 2Ω
Effective resistance of 3Ω and 6Ω connected in parallel R is
`1/"R" = 1/3 + 1/6`
= `3/6`
= `1/2`
∴ R = 2Ω
Total resistance = (R + r)
= (2 +2)
= 4Ω
(a) Current through battery
I = `"V"/("R" + r) = "E"/("R" +r)`
I = `(16V)/(4Ω)`
= 4 A
(b) p.d between terminal of battery
V = IR
= 4 × 2
= 8V
(c) The current in 3Ω resistor
I1 = `"V"/"R"`
= `8/3`
= 2.66 A
(d) The current in 6Ω resistor
I2 = `"V"/"R"`
= `8/6`
= 1.34 A
APPEARS IN
RELATED QUESTIONS
Complete the following :-
(b)
What are the advantages of connecting electrical devices in parallel with the battery instead of connecting them in series?
Several electric bulbs designed to be used on a 220 V electric supply line are rated 10 W. How many lamps can be connected in parallel with each other across the two wires of 220 V line if the maximum allowable current is 5 A?
Show with the help of diagrams, how you would connect three resistors each of resistance 6 Ω, so that the combination has resistance of (i) 9 Ω (ii) 4 Ω.
State how are the two resistors joined with a battery when potential difference is same across each resistor.
A combination consists of three resistors in series. Four similar sets are connected in parallel. If the resistance of each resistor is 2 ohm, find the resistance of the combination.
The circuit diagram Fig shows three resistors 2 Ω, 4 Ω and R Ω connected to a battery of e.m.f. 2 V and internal resistance 3 Ω. If main current of 0.25 A flows through the circuit, find:
- the p.d. across the 4 Ω resistor,
- the p.d. across the internal resistance of the cell,
- the p.d. across the R Ω or 2 Ω resistors
- the value of R.
A particular resistance wire has a resistance of 3 ohm per meter. Find the potential difference of the battery which gives a current of 2 A in each of the 1.5 m length when connected in the parallel to the battery (assume that resistance of the battery is negligible).
Three resistors of 6Ω, 4Ω and 4Ω are connected together so that the total resistance is 8Ω. Draw a diagram to show this arrangement and give reason to justify your answer.
Two resistors having resistance 8 Ω and 12 Ω are connected in parallel. Find their equivalent resistance.
