The conduction of heat can take place within an object or between any two objects in contact with each other. It stops when the objects obtain the same temperature

How does the force of gravitation between two objects change when the distance between them is reduced to half ?

Two forces of magnitudes 3N and 4 N act together on an object making an angle 60^(@) with each other. Find the resultant force acting on the object.

A charge Q is to be divided on two objects. What should be the values of the charges on the objects so that the force between the objects can be maximum?

Is there any connection between object's feeling hot or cold and its thermal conductivity ?

A convex lens of focal length f_(1) is placed in front of a luminous point object. The separation between the object and the lens is 3f_(1) . A glass slab of thikness t is placed between the object and the lens. A real image of the object is formed at the shortest possible distance from the object. a. Find the refractive index of the slab. b. If a concave lens of very large focal length f_(2) is placed in contact with the convex lens, find the shifting of the image.

Two identical objects A and B are at temperatures T_A and T_B . Respectively. Both objects are placed in a room with perfectly absorbing walls maintained at a temperature T(T_AgtTgtT_B) . The objects A and B attain the temperature T eventually. Select the correct statements from the following:

Two identical objects A and B are at temperatures T_A and T_B . Respectively. Both objects are placed in a room with perfectly absorbing walls maintained at a temperature T(T_AgtTgtT_B) . The objects A and B attain the temperature T eventually. Select the correct statements from the following:

(a) Two protons are placed at some separation in vacuum. Find the ratio of electric and gravitational force acting between them. (b) Two point charges are placed at separation 3 m in vacuum. What can be the minimum force between them. (c ) A charge Q is to be divided on two objects. What should be the value of the charges in the objects so that the force between them is maximum ? (d) Two insulating small spheres are rubbed against each other and placed 1.6 cm apart. If they attract each other with a force of 0.9 N , how many electrons were transferred from one sphere to the other during rubbing ?

An object is placed at a distance of 30 cm from a converging lens of focal length 15 cm. A normal eye (near point 25 cm, far point infinity) is placed close to the lens on the other side. (a) Can the eye see the object clearly? (b) What should be the minimum separation between the lens and the eye so that the eye can clearly see the object? c. Can a diverging lens, placed in contact with the converging lens, help in seeing the object clearly when the eye is close to the lens?

"A concave mirror of focal length 'f' can form a magnified erect as well as an inverted image of an object placed in front of it. " Justify this statement stating the position of the object with respect to the mirror in each case for obtaining these images.