1. Which has no importance for fuse wire –
(a) Specific resistance of wire
(b) Diameter of wire
(c) Length of wire
(d) Current passing through the wire
2. The specific resistance of a wire varies with its –
(a) Length
(b) Cross-section
(c) Mass
(d) Material
3. The unit of specific resistance is –
(a) ohm
(b) ohm–1
(c) ohm-metre
(d) ohm per metre
4. How many electrons constitute a current of one microampere –
(a) 6.25 × 10^6
(b) 6.25 × 10^12
(c) 6.25 × 10^9
(d) 6.25 × 10^15
5. Good conductors have many loosely bound –
(a) atoms
(b) protons
(c) molecules
(d) electrons
6. The variable resistance is called –
(a) resistor
(b) rheostat
(c) open switch
(d) none of these
7. If the length of a wire is doubled and its cross-section is also doubled, then the resistance will –
(a) increase eight times
(b) decrease four times
(c) become four times
(d) remain unchanged
8. Instruments can be shielded from outside magnetic effects by surrounding them with
(a) Iron shield
(b) Rubber shield
(c) Brass shield
(d) Glass shield
9. The following is a pseudo-force:
(a) Centrepetal force
(b) Centrifugal reaction force
(c) Centrifugal force
(d) Strong nuclear force
10. The hydraulic brake used in automobiles is a direct application of
(a) Archimedes’ principle
(b) Torricellean law
(c) Bernoulli’s Theorem
(d) Pascal’s law
Answers Key :
1.(c)
2.(d)
3.(c)
4.(b)
5.(d)
6.(b)
7.(c)
8.(c)
9.(c)
10.(d)
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