Question 4 - Case Based Questions (MCQ) - Chapter 12 Class 10 - Electricity

Two conductors A and B of resistances 5 Ω and 10 Ω respectively are first joined in parallel and then in series. In each case the voltage applied is 20 V. Answer any four questions from (a) to (e).

Question 4 (a)

Draw the circuit diagram to show connection when A and B are joined in parallel?

Answer:

Circuit (i) is the correct circuit diagram.

Question 4 (b)

In which combination will the voltage across the conductors A and B be the same?

(i) Series arrangement

(ii) Parallel arrangement

(iii) Both of the above

(iv) None of the above

Answer:

In parallel circuits , the potential difference across each resistor is the same.

So, the correct answer is (ii)

Question 4 (c)

In which arrangement will the current through A and B be the same?

(i) Series arrangement

(ii) Parallel arrangement

(iii) Both of the above

(iv) None of the above

Answer:

In series circuits , the current across each resistor is the same.

So, the correct answer is (i)

Question 4 (d)

Equivalent resistance in parallel combination is: 

(i) 15 Ω

(ii) 3.33 Ω

(iii) 0.3 Ω

(iv) None of the above

Answer:

Let R be the equivalent resistance in the parallel combination.

1 / R = 1 / 5 + 1 / 10

         = (2 + 1) / 10 

         = 3 / 10

Therefore, R = 10/3 = 3.333 ohm

So, the correct answer is (ii)

Question 4 (e)

Equivalent resistance in series combination is: 

(i) 15 Ω

(ii) 3.33 Ω

(iii) 0.3 Ω

(iv) None of the above

Answer:

Let R be the equivalent resistance in the series combination.

R = 5 + 10 

     = 15 ohm

So, the correct answer is (i)