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A copper ball of mass 100 gm is at a temperature T. It is dropped in a copper calorimeter of mass 100 gm, filled with 170 gm of water at room temperature. Subsequently, the temperature of the system is found to be 75°C. T is given by : (Given : room temperature = 30° C, specific heat of copper = 0.1 cal/gm°C (1) 1250°C (2) 825°C (3) 800°C (4) 885° C

A copper ball of mass 100 gm is at a temperature T. It is dropped in a copper calorimeter of... View Article

Certain force acting on 20 kg mass changes its velocity from 5 m/s to 2 m/s. Calculate the work done by the force

Answer: Work is said to be done when a force applied to an object moves that object. Work done is... View Article

What are the changes seen in girls at the time of puberty?

Puberty is when a child’s body begins to develop and change as they become an adult. At the time of... View Article

Oestrogen and testosterone are steroid hormones, and they most likely bind to

Steroid hormones are lipophilic in nature. The lipids present in the cell membranes do not prohibit the entry of lipophilic... View Article

Give an example of displacement reaction.

Displacement reaction is a reaction in which an atom, or a group of atoms, present in a molecule is displaced... View Article

An electric motor takes 5 A from a 220 V line. Determine the power of the motor and the energy consumed in 2 h.

Answer: Given parameters Voltage (V) = 220 V Current (I) = 5 A Time (t) = 2 h = 2... View Article

In evolutionary terms, can we say which among bacteria, spiders, fish and chimpanzees have a better body design? Why or why not?

No, we cannot say that there is a better body design as these organisms evolved according to their needs to... View Article

Fill in the blanks:(i) The average weather taken over a long time is called (fill in the blank). (ii) A place receives very little rainfall and the temperature is high throughout the year, the climate of that place will be (fill in the blank)and (fill in the blank). (iii) The two regions of the earth with extreme climatic conditions are (fill in the blank) and (fill in the blank).

(i) The average weather taken over a long time is called climate. (ii) A place receives very little rainfall and... View Article

Which blood vessel carries blood from the kidneys back to the heart?

The renal vein leaves the kidneys and carries the blood back to the heart. Since the kidneys extract the nitrogenous... View Article

Explain anti-Markovnikov’s rule.

Anti-Markovnikov rule explains the regiochemistry where the substituent is bonded to a less substituted carbon, rather than the more substitued... View Article

The length of a long rod is measured first by using pace-span and then, by using foot-span of a person. For the person, the length of one pace-span is four times the length of one foot-span. If the length of the rod is 6 pace-spans, then what is the length of the rod in terms of foot-span?

It is given that the length of one pace-span is four times the length of one foot-span. Therefore, 1 pace-span... View Article

What are the factors that affect the rate of corrosion?

Answer: Corrosion is defined as the natural process that causes the conversion of pure metals to undesirable substances when they... View Article

There are four mirrors labelled as I, II, III, and IV. Mirrors I and IV can form virtual and small images only. Mirror III can form an image that can be obtained on a screen. Mirror II cannot form real images of objects. Which of the given mirrors can form an inverted image of the object?”

The image formed by mirror III can be obtained on a screen. Hence, mirror III can form a real image.... View Article

An object experiences a net zero external unbalanced force. Is it possible for the object to be travelling with a non-zero velocity? If yes, state the conditions that must be placed on the magnitude and direction of the velocity. If no, provide a reason.

Yes, an object may travel with a non-zero velocity even when the net external force on it is zero. An object... View Article

Why are ionic compounds are soluble in water but insoluble in kerosene?

The ionic compounds are held together by ionic bonds and categorized as ionic compounds. The crystalline solids are formed by neatly... View Article

A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force. Let us take it that the force acts on the object through the displacement. What is the work done in this case?

Answer: When a force F acts on an object to move it in its direction through a distance S, the... View Article

Process involving movement of substances against the concentration gradient using ATP.

Active transport is the process involving movement of substances against the concentration gradient using ATP. The reason the process is... View Article

Name sources of energy that are not ultimately derived from the sun’s energy? a)Bio-mass b)Geothermal energy c)Wind energy d)Nuclear energy

The correct option is d) Nuclear energy The energy that is required for fusing two nuclei is provided by the... View Article

Explain why coils of electric toasters and electric irons made of an alloy rather than a pure metal?

Coils of electric toasters and electric irons made of an alloy rather than a pure metal due to the following... View Article

What is the sum of the numbers 6.68 and 0.8?

During addition, the result cannot have more digits to the right of the decimal point than either of the original... View Article

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