What is the correct energy transformation during burning of a candle?

1. heat → kinetic + potential
2. heat → chemical + light
3. chemical → heat + light
4. mechanical → chemical + heat

When a ray of light passes from one optical medium to another, which of the following physical quantities does NOT change?

1. Amplitude of the wave
2. Frequency of the wave
3. Wavelength of the wave
4. Speed of the wave

For a lever, a graph is plotted with load on Y-axis and effort on X-axis. Which of the following represents the slope of the graph?

1. Mechanical advantage
2. Velocity ratio
3. $\dfrac{1}{\text {Velocity ratio}}$
4. $\dfrac{1}{\text {Mechanical advantage}}$

For a real image formed by a convex lens, the ratio of I : O = 2 : 5, then the object is :

(I is the height of the image and O is the height of the object)

1. between O and F
2. beyond 2F
3. at F
4. between F and 2F