#### Electricity Model Question Paper

10th Standard

Reg.No. :
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Science

Time : 01:00:00 Hrs
Total Marks : 50
5 x 1 = 5
1. Give the name of components which is designed to oppose the flow of current.

(a)

Capacitor

(b)

Resistors

(c)

Fuse wire

(d)

Inductor

2. The resistance of a conductor directly proportional to

(a)

Length

(b)

Area

(c)

Volt

(d)

Current

3. The resistance of a conductor is inversely proportional to its _______.

(a)

Volt

(b)

Length

(c)

Area

(d)

None ofthe above

4. What happens when ammeter connected in parallel?

(a)

Open circuited

(b)

Closed Circuited

(c)

Short circuited

(d)

None of the above

5. If resistance of a wire is r ohms and wire is stretched to double its length, then what is its resistance?

(a)

r

(b)

2r

(c)

4r

(d)

r/2

6. 4 x 2 = 8
7. Write electrical use of the components in electrical circuit.

8. How does a parallel circuit differ from a series circuit?

10. Electrical resistivities of some substances at 200 C are given below:

 Silver 1.60 x 10-8Ω- m Copper 1.62x10-8Ω-m Tungsten 5.20 x 10-8Ω - m Iron 10.0 x 10-8Ω-m Mercury 94.0 x 10-8Ω-m Nichrome 10.0 x 10-8Ω-m

Answer the following question in relation to them:
(i) Among silver and copper, which one is a better conductor? Why?
(ii) Which material would you advise to be used in electrical heating devices? Why?

11. 4 x 4 = 16
12. A piece of wire having a resistance R is cut into five equal parts.
a) How will the resistance of each part of the wire change compared with the original resistance?
b) If the five parts of the wire are placed in parallel, how will the resistance of the combination change?
c) What will be ratio of the effective resistance in series connection to that of the parallel connection?

13. Water boils in an electric kettle in 15 mins. after switching on. If the length of the heating wire is decreased to $\frac{1}{3}$ of its initial value, then in how much time will the same amount of water boil with the same supply voltage?

14. Write any five electrical components used in electrical circuit and draw its symbol.

15. Kalaivani was watching at a metal pipe, one end of which is connected to a tank at the top of her building and the other end to the tap, which is near the ground level. She was admiring how the water flows from top to the bottom through the pipe. She went and asked her mother, who was an engineer.
(i) Also Kalaivani asked her mother that can she able to compare this with any other scientific concepts?
(ii) How would her mother have compared
the resistance in a water pipe as well as in a conductor.
(iii) Give the expression for resistors connected in series and parallel.

16. 3 x 7 = 21
17. A current of 6 A flows through metal wire. How many coulombs of charge pass through the wire in 2 miniatures?

18. The potential difference between two conductor is 110 V. How much work in moving 5 C charge from one conductor to the other?

19. Determine the following quantities of the
given equivalent.
(i) The equivalent resistance
(ii) Total current through the circuit
(iii) The current through each resistor
(iv) Voltage drop across resistor
(v) Power dissipated in each resistor

R= 20Ω; R= 100Ω;R350Ω; V  =125V