ING Search

Q:

Skating on ice is possible because

A) the surface of ice is smooth	B) ice is cold
C) the pressure on the ice due to skate melts the ice by lowering its melting point forming a thin film of water	D) the pressure on the ice due to skate raises its melting point

Answer & Explanation Answer: C) the pressure on the ice due to skate melts the ice by lowering its melting point forming a thin film of water

Explanation:

Here is a case of lowering of melting point of ice with increase of pressure

Report Error

View Answer Report Error Discuss

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.

Report Error

View Answer Report Error Discuss

Filed Under: Physics

Q:

A man stands on the pan of a balance holding a fish in his right hand and bucket of water in his left hand. If he transfers the fish into the bucket, the total weight on the pan

A) increases	B) decreases
C) remains the same	D) first increases and then decreases

Answer & Explanation Answer: C) remains the same

Explanation:

Before transferring the fish, the position is the man with the fish and the bucket of water. After transferring the position is : the man without the fish, but the fish inside the water in the bucket. Thus to know whether there is any change in weight, it is enough to consider whether there is any change in weight when the fish in air is transferred into the water. The answer is there is no change as when in water though it loses weight due to upthrust of water on it, the level of water increases and exerts an equal force at the bottom

Report Error

View Answer Report Error Discuss

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

Report Error

View Answer Report Error Discuss

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.

Report Error

View Answer Report Error Discuss

Filed Under: Physics

Q:

A bucket of water is hung from a spring balance. A piece of iron is suspended in the water without touching the sides or touching the bottom of the bucket. The reading of the spring balance

A) will increase	B) will decrease
C) does not change	D) varies with the increase of depth of the immersion of the iron piece

Answer & Explanation Answer: A) will increase

Explanation:

When the piece of iron is lowered into the water, the water level in the bucket increases. And so the pressure at the bottom of bucket also increases. Thus the total thrust at the botto also increases. Therefore the spring balance reading increases.

Report Error

View Answer Report Error Discuss

Filed Under: Physics

Q:

A piece of ice is floating in water kept in a beaker. When all the ice melts the level of water will

A) first rise and then fall	B) fall
C) remain the same	D) rise

Answer & Explanation Answer: C) remain the same

Explanation:

The submerged portion of the ice on melting shrinks a little in volume. so the level of water goes down a little.But this is just made up by the water added by the melting of upper portion. Addition is equal to the Shrinkage. Hence level is unchanged.

Report Error

View Answer Report Error Discuss

Filed Under: Physics

Q:

A man jumping out of a moving train is thrown

A) forward	B) backward
C) sidewaqys	D) None of these

Searching for "ING"

Quick Links