Question

4. A letter A is constructed of a uniform wire of
resistance 1 ohm per cm. The sides of the letter are
20 cm and the cross piece in the middle is 10 cm long.
The resistance between the ends of the legs will be
(a) 32.4 ohm
(b) 28.7 ohm
(c) 26.7 ohm
(d) 24.7 ohm​

Answer 1

Explanation:

Now the length of the cross piece in the middle is 10 cm and the other two sides of the letter are 20 cm each. Now the cross piece divides the arms of the letter in two equal parts, and as such, the resistance of each unit can be given as r= 1 Ω/cm×10cm=10Ω .