Suupose a helical spring is suspended from the roof and a very small weight is attached to its lower end. What will happen to the spring when the current is passed thorugh it? Give reason to support your answer.

A heavy wire is suspended from a roof but no weight is attached to it lower end. Is it under stress. Explain?

Direction. In the follwing questions, a statement of assertion is followed by a statement of reason. While answering a question, you are required to choose the correct are out of the given four responses and mark it as (A). If both assertion and reason are true and reason is the correct explanation of the assertion, (B) if both assertion and reason are true but reason is not correct explanation of the assertion. (C) if asssertion is true, but reason if false, (D) if both assertion and reason are false Assertion : The coils of a spring come close to each ohter, when current is passed thorugh it. REason : It is becuase, the coils o spring carry current in the same direction and hence attract each other.

A door is hinged at one end and is free to rotate about a vertical axis. (show in the figure) Does its weight cause any torque about this axis ? Give reasons for your answer.

A body of mass m is attached to one end of a massless spring which is suspended vertically from a fixed point. The mass is held in hand so that the spring is neither stretched nor compressed. Suddenly the support of the hand is removed. The lowest position attained by the mass during oscillation is 4 cm below the point, where it held in hand. What is the amplitude of oscillation?

A body of mass m is attached to one end of a massless spring which is suspended vertically from a fixed point. The mass is held in hand so that the spring is neither stretched nor compressed. Suddenly the support of the hand is removed. The lowest position attained by the mass during oscillation is 4 cm below the point, where it held in hand. Find the frequency of oscillation?

An elastic spring has a mass suspended at its lower end, its upper end being fixed to support. The mass is puled down to a certain distance and released. Calculate the time period of its oscilaltions.

A soft spiral spring hangs freely. The lower end of the spring is immersed in a cup of mercury. The spring and the cup are connected to a source of direct current as shown in Fig.. What will happen to the spring after switch K is closed?