Electricity — Science STD 10 — Question

Using the circuit given below, state which of the following statement is correct?
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1. When S₁ and S₂ are closed, lamps A and B are lit.₂2
2. With S₁ open and S₂ closed, A is lit and B is not lit.
3. With S₂ open and S₁ closed A and B are lit.
4. With S₁ closed and S₂ open, lamp A remains lit even if lamp B gets fused.

The refractive index of water is:

Connecting wires in a electric circuit are made of .......?

A young man has to hold a book at arm's length to be able to read it clearly. The defect of vision is:

1. Astigmatism.
2. Myopia.
3. Presbyopia.
4. Hypermetropia.

The focal lengths of four convex lenses P, Q, R and S are 20cm, 15cm, 5cm and 10cm, respectively. The lens having greatest power is:

1. P
2. Q
3. R
4. S

If R₁ and R₂ be the resistance of the filament of 40W and 60W respectively operating 220V, then:

If the area of cross-section of a resistance wire is halved, then its resistance becomes:

1. One-half.
2. 2 times.
3. One-fourth.
4. 4 times.

A person cannot see the distant objects clearly (though he can see the nearby objects clearly). He is suffering from the defect of vision called:

1. Cataract.
2. Hypermetropia.
3. Myopia.
4. Presbyopia.

Work done to move 1 coulomb charge from one point to another point on a charged conductor having potential 10 volt is:

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

1. 93
2. 193
3. 293
4. 393