High Order Thinking Skills (HOTs) - 2 - Class 9 MCQ

The molecular weight of water (H₂O) is 18 grams (2 grams of hydrogen + 16 grams of oxygen). Therefore, 9 grams of water contains 1 gram of hydrogen and 8 grams of oxygen.

According to the balanced equation, for every 6 molecules of CO₂  consumed, 6 molecules of O₂  and 1 molecule of glucose are produced. Therefore, consuming 12 molecules of CO₂ will produce 12 molecules of O₂ and 2 molecules of glucose.

Newton's first law is known as the law of inertia. It implies that in the absence of a net force, the velocity of an object remains constant.

The atomic number is the number of protons, which is 15. The mass number is the sum of protons and neutrons, which is 15 + 16 = 31.

The element with atomic number 17 is chlorine, which belongs to group 7 and period 3 in the periodic table.

Organelles (i), (ii), (iii) and (iv) shown in the given figures are mitochondrion, Golgi body, chloroplast and endoplasmic reticulum respectively. Chloroplast and mitochondria contain their own DNA, RNA and ribosomes hence are called semi-autonomous organelle.

The plant tissues shown in the given figure (i) and (ii) are parenchyma and sclerenchyma respectively. Parenchymatous tissue is present in mesophyll of leaves whereas sclerenchymatous tissue is present in husk of coconut.

Milk is an emulsion, i.e., liquid in liquid type of colloid. Solid foam is a colloid in which a gas is dispersed in a solid medium e.g., sponge. Sol is a colloid in which tiny solid particles are dispersed in a liquid medium e.g., milk of magnesia.
Aerosol is a colloid in which liquid particles are dispersed in the gaseous medium e.g., fog.
Milky glass is a solid sol (solid dispersed in solid medium) and not an aerosol

By the given figure,

(i) Impulse = Area of F.t curve = Area of ∆POQ + Area of rectangle PQSR + Area of ∆RSW

(ii) Impulse = change in momentum 12 = m × 0 + mv (As, initially particle is at rest)

(iv) The average force exerted on the particle for time interval 0 to 5 s is

Since, force on the vehicle is constant, it will move with a constant acceleration. For particle starting from rest, velocity, v = at

∴ Graph of E versus t will be parabola of increasing slope. Thus, graph (iv) is correct.
Power associated with force is equal to, P = Fv = Fat Thus, graph of P versus t will be a straight line. Hence, graph (i) is correct. And graphs (ii) and (iii) are incorrect.