Magnetic Effects of Electric Current — Science STD 10 — Question

To convert an AC generator into DC generator:

1. Split-ring type commutator must be used.
2. Slip rings and brushes must be used.
3. A stronger magnetic field has to be used.
4. A rectangular wire loop has to be used.

Which of the following ray diagrams is correct for the ray of light incident on a lens shown in Fig.?

In a nuclear power plant, coolant is a substance:

1. Which cools the hot, spent steam to condense it back to water.
2. Which transfers heat from reactor to water in heat exchanger.
3. Which is boiled to make steam to turn the turbine.
4. Which cools the generator coils to prevent their overheating.

An uncontrolled nuclear chain reaction forms the basis of:

1. Nuclear power plant.
2. Hydrogen bomb.
3. Thermal power station.
4. Atom bomb.

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.

Name the colour of white light which is deviated the least, on passing through a prism:

Four identical wires each having resistance R are connected as shown in the figure. Equivalent resistance between A and B is:

Which amongst the given radiation is preferred for taking photographs in fog?

Magnification produced by a convex mirror is always:

The path of a ray of light passing through a glass prism is shown below:

In this diagram the angle of prism, angle of incidence, angle of emergence and angle of deviation respectively have been represented by: