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Q:

European Turkey is separated from its Asian part by

A) Straits of Bosporus B) Sea of Marmara
C) Straits of Dardanelles D) All the above
 
Answer & Explanation Answer: D) All the above

Explanation:
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Filed Under: World Geography

Q:

Formation of shadows can be explained by 

A) rectilinear propagation of light B) reflection
C) refraction D) total internal reflection
 
Answer & Explanation Answer: A) rectilinear propagation of light

Explanation:

In this position, the head light will be at the principal focus so that the rays of light falling on the cancave mirror will be rendered parallel

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Filed Under: Physics

Q:

Radio waves sent out by a radio stations are reflected by

A) troposphere B) stratosphere
C) mesosphere D) ionosphere
 
Answer & Explanation Answer: D) ionosphere

Explanation:

This is a layer of atmosphere about 60 to 70 km above the earth and extends to about 400km. It contains ionised particles which can reflect radio waves making radio communication round the world possible.

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Filed Under: Physics

Q:

A cup of hot coffee is placed on a metal table in a room. By which of the following methods does it lose heat?

A) conduction and convection only B) conduction and radiation only
C) convection and radiation only D) conduction, convection and radiation
 
Answer & Explanation Answer: D) conduction, convection and radiation

Explanation:

Part of the heat is conducted away by the metal table. Convection currents in air near the surface of the coffee are set up which accounts for some heat loss. Heat is also lost by radiation from the hot coffee to the surroundings. Most of the heat is lost by the last method.

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Filed Under: Physics

Q:

For accurate scientific work, temperatures are often measured by

A) mercury thermometers B) alcohol thermometers
C) platinum resistance thermometers D) thermoelectric thermometers
 
Answer & Explanation Answer: C) platinum resistance thermometers

Explanation:

The resistance of metallic conductors e.g, platinum, increases with rise of  temperature . The increase in temperature results in a decrease of current which can be recorded in a galvanometer if the conductor is included in an electrical circuit. Thus the temperature can be known; platinum resistance thermometer is used generally for accurate scientific work. When two dissimilar metals are joined at the ends, and these ends are subjected to a difference of temperature, a current flows through the metals. Greater the difference of temperature , greater the current. So the curent strength can form the basis for measuring the difference in temperature. And when one of these temperatures is known, we can calculate the other.

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Filed Under: Physics

Q:

The fact that two large ships travelling on close parallel courses in the same direction tend to move towards each other can be explained by

A) Bernoulli's principle B) Magnetic properties of the ship's material
C) Newton's third law of motion D) Earth's gravitational force
 
Answer & Explanation Answer: A) Bernoulli's principle

Explanation:

The rapid flow of air between the two moving ships causes a reducton of pressure (Bernoulli's principle) , so they (the ships) are drawn closer together

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Filed Under: Physics

Q:

A capillary tube is partially dipped vertically in a vessel containing water. Due to capillarity water rises in the tube. The height of water rise in the tube can be increased by 

A) decreasing the radius of the capillary tube B) increasing the radius of the capillary tube
C) increasing the height of water in the vessel D) None of these
 
Answer & Explanation Answer: A) decreasing the radius of the capillary tube

Explanation:

The water rise in a capillary tube dipped in water is such that the weight of water in the tube above the surface of water in the vessel is equal to  the upward force due to surface tension. So it is clear that if the bore to the tube is decreased , the height of the water column in it  must be greater.

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Filed Under: Physics

Q:

The playback singer who is certified as the 'Most Recorded Artist' in the world (2009) by the World Records Academy is ________

Answer

Asha Bhosle . She  is the sister of Latha Mangeshkar

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