Q1. Two wires A and B have the same cross-section and are made of the same material. Ra =600 ohm ad Rb =100 ohm. The number of times A is longer than B is
(a) 6 (b)2 (c) 4 (d)5
Ans: a
Q2. Two copper conductor have same length but one has cross-section twice that of the other. If thicker has a resistance of 20 ohm, the resistance of the other is ____________ohm
(a)10 (b)40 (c)20 (d)60
Ans:b
Hint : A1= 2A2
Q3. Which of the following material has nearly zero temperature coefficient of resistance ?
(a)manganin (b)porcelain (c)copper (d)carbon
Ans:a
Q4. Which of the following does not have negative temperature coefficient ?
(a)Paper ( b)Aluminium (c) Rubber (d) Mica
Ans: b
Q5. Resistance of a material always decreases if
(a) temperature of material is decreased
(b) temperature of material is increased
(c) number of free electrons available become more
(d) none of the above is correct
Ans: c
No comments:
Post a Comment