Question

Please answer the following two questions​

Answer 1

Explanation:

19) If you observe carefully then 6 ohm and 12 ohm resistor are in series.

equivalent resistance is 6+12= 18 ohm

20) 1/ R equivalent = 1/15+x+ 1/10

20/3= 1/15+x+ 1/10

solve this and get your answer

Answer 2

Answer:

19.

(a) Here two resistors of 6 ohms and 12 ohms are connected in series

Req when two resistors are connected in series = R1+R2

Req = 6+12

Req = 18 ohms

The effective resistance across the circuit is 18 ohms

(b) V=IR

V = 9V

R = 18 ohms

I = 9/18 = 0.5 Amperes

Pottential difference in 6 ohms resistor = 0.5×6

Potential difference in 6 ohms resistor = 3 Volts

Potential difference in 12 ohms resistor = 0.5×12

Potential difference in 12 ohms resistor = 6 Volts

The potential difference is 3 Volts and 6 Volts respectively

(c) power dissipated in 6 ohms resistor = I²R

= 0.5²×6

= 0.25×6

= 1.5 watts

The power dissipated is 1.5 watts

20.

15 and X are in series = 15+X

15+X is in parallel to 10 ohms resistor:

20/3 = 15+X×10/15+X+10

20/3 = 150+10X/25+X

Cross multiplying :

450+30X=500+20X

50 = 10X

X=50/10

X=5 ohms

The value of x is 5 ohms