Question

9. Please refer to the circuit diagram below and answer the questions that follow:

a) Find the equivalent resistance of the circuit.
b) What would be the reading in the ammeter?
c) Find the potential difference ACROSS the 3 ohm resistor.
d) How much energy is dissipated by the 5 ohm resistor in 2 mins?​

Answer 1

Answer:

a)2.5 ohm

b)1.6 A

c)2.4 V

d)384 J

Step-by-step explanation:

a) This circuit has a parallel combination in which 3 ohm & 2 ohm are in series. So the total equivalent resistance in lower arm= 3+2 = 5 ohm

Now both 5 ohm of upper arm & 5 ohm of lower arm are parallel.

So the equivalent resistance = ( 5*5 ) / 5 + 5

= 25/10

= 2.5 ohm

b) Reading in Ammeter = Total current flowing in circuit

Total potential difference in circuit = 4V

Total Equivalent resistance = 2.5 ohm

Total current flowing in circuit = V/R

= 4/2.5

= 1.6 A

c) The current will get split equally in the parallel combination setup because equivalent resistance in both arms is equal

Current flowing in lower arm = 1.6/2 = 0.8 A

Potential difference across 3 ohm resistor =

0.8 × 3 = 2.4 V

d) Power(P) = (I)^2 / R ; Energy(E) = P × time(t)

Power of the 5 ohm resistor =(0.8)^2 × 5 = 3.2W

Energy dissipated by 5 ohm resistor = 3.2 × 2 mins= 3.2 × 120 secs= 384 J