A spring of length 25cm is extended to 30cm by a load of 150N attached to one of its end, what is the energy stored in the spring?

• A. 3750J
• B. 2500J
• C. 3.75J
• D. 2.50J

A body of mass 11kg is suspended from a ceiling fan by an aluminum wire of length 2m and diameter 2mm. Calculate the elastic energy stored in the wire [Young's modulus of aluminum is 7.0 x 10¹⁰Nm^-2, g = 10ms^-2, \(\pi\) = 3.142]`

• A. 1.1 x 10^-1J
• B. 5.5 x 10^-2J
• C. 1.1 x 10^-4J
• D. 5.5 x 10^-8J

Why do soldiers march disorderly while crossing a bridge?

• A. To prevent resonance on the bridge
• B. To set the bridge into resonance
• C. To make the b ridge collapse
• D. To spread their weight evenly on the bridge

The diagram below represents balls in an undulating surface. Which of the following option represents positions of stable equilibrium?

• A) III, IV and VIII
• B) II, V and VIII
• C) III, VI and IX
• D) I, IV and VII

Two objects, A and B, accelerate from rest at uniform rates. B accelerates twice as much as Compared to A, B travels

• A. at the same distance as A
• B. six times as far.
• C. two times as far
• D. three times as far

Shadows and eclipse result from the

• A. Reflection of light
• B. Rectilinear propagation of light
• C. Diffraction of light
• D. Refraction of light

The use of lenses is Not applicable in the

• A. projector
• B. human eye
• C. periscope
• D. telescope

The functional difference between a lens and a mirror is that a lens

• A. reflects a beam of light while a mirror refracts it
• B. refracts a beam of light while a mirror reflects it
• C. absorbs incident rays while a mirror transmit them
• D. transmits incidents ray whle a mirror absorbs them

A thin wire with heavy weights attached to both ends is hung over a block of ice resting on two supports. If the wire cuts through the ice block while the block remains solid behind the wire, the process is called

• A. condensation
• B. sublimation
• C. regelation
• D. fusion

State three observable phenomena in which waves behave like a particle.