15 Questions

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Questions and Answers

- 1.An electrical appliance has a resistance of 25 Ω. When this electrical appliance is connected to a 230 V supply line, the current passing through it will be:
- A.
0.92 A

- B.
2.9 A

- C.
9.2 A

- D.
92 A

- 2.
- A.
1/9 V

- B.
1/2 V

- C.
2V

- D.
1V

- 3.Two electric bulbs have resistances in the ratio 1:2. If they are joined in series, the energy consumed in them is in the ratio.
- A.
2:1

- B.
1:2

- C.
4:1

- D.
1:1

- 4.
- A.
Ammeter A

- B.
Ammeter B

- C.
Ammeter C

- D.
Ammeter D

- 5.
- A.
4Ω

- B.
6Ω

- C.
9Ω

- D.
18Ω

- 6.If the current flowing through a fixed resistor is halved, the heat produced in it will become:
- A.
One-fourth

- B.
One-half

- C.
Double

- D.
Four times

- 7.Two bulbs marked 200 watt-250 volts and 100 watt-250 volts are joined in series to 250 volts supply. Power consumed in circuit is
- A.
33 watt

- B.
67 watt

- C.
100 watt

- D.
300 watt

- 8.What is the amount of current flowing through an electric press, if the amount of charge passing through a conductor in 10 minutes is 300 C?
- A.
30 A

- B.
0.3 A

- C.
0.5 A

- D.
5 A

- 9.When a current 'I' flows through a resistance 'R' for time 't' the electrical energy spent is given by
- A.
IRt

- B.
I

^{2}Rt - C.
IR

^{2}t - D.
I

^{2}R/t

- 10.V
_{1}, V_{2}and V_{3}are the potential differences across the 1Ω, 2Ω and 3Ω resistors in the following diagram, and the current is 5A. Which of the following shows the correct values of V_{1}, V_{2}and V_{3}measured in volts?- A.
V

_{1}=1, V_{2}= 2 and V_{3}= 3 - B.
V

_{1}=5, V_{2}= 10 and V_{3}= 15 - C.
V

_{1}=5, V_{2}= 2.5 and V_{3}= 1.6 - D.
V

_{1}=4, V_{2}= 3 and V_{3}= 2

- 11.A wire of resistance R
_{1}is cut into five equal pieces. These five pieces of wire are then connected in parallel. If the resultant resistance of this combination be R_{2}, then the ratio R_{1}/ R_{2}is:- A.
1/25

- B.
1/5

- C.
5

- D.
25

- 12.At a given time, a house is supplied with 100 A at 220 V. how many 75 W, 220 V light bulbs could be switched on in the house at the same time (if they are all connected in parallel)?
- A.
93

- B.
193

- C.
293

- D.
393

- 13.Keeping the potential difference constant, the resistance of the circuit is halved. The current will become:
- A.
One-fourth

- B.
Four times

- C.
Half

- D.
Double

- 14.When a 4 Ω resistor is connected across the terminals of a battery, the number of coulombs passing through the resistor per second is:
- A.
0.3

- B.
3

- C.
4

- D.
12

- 15.In the figure,
- A.
6 W, 3 W and 9 W are in series

- B.
9 W and 6 W are in parallel and the combination is in series with 3 W

- C.
3 W, 6 W and W are in parallel

- D.
3 W, 6 W are in parallel and 9 W is in series