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To investigate the conditions for rusting, following experiment was performed.

In which test tube, nails rusted most heavily and what inference can be drawn from it?

(A) Test tube P, water is needed for rusting.

(B) Test tube Q, air is needed for rusting.

(C) Test tube R, boiled water increases the rusting speed.

Which of the following statements is/are correct?
I. 5 moles of CO₂ and 5 moles of H₂O have the same mass.
II. 100 g of NH₃ has more atoms than that present in 100 g of N_2.
III. 16 g of solid sulphur contains 3.76 × 10²² molecules.

A I and II only
B II and III only
C III only
D I only

A force of 12 N acts on a block P and block Q of masses 2 kg and 4 kg respectively as shown. Given that the floor is smooth, find the force on the string between blocks P and Q.


A 2 N
B 4 N
C 8 N
D 12 N

A boy runs for 10 minutes at a uniform speed of 9 km h^-1. At what speed should he run for the next 20 minutes so that the average speed comes to 12 km h^-1?

A 13.5 km h^-1
B 10.2 km h^-1
C 8.2 km h^-1
D 7.72 km h^-1

Which of the following does not represent characteristic of a good fuel?

A It should have a high calorific value.
B Its ignition temperature should be low but well above the room temperature.
C It should have a high rate of combustion.
D It should be fairly cheap and safe to handle and transport.

Given statements show different steps involved in digestion of food. Select the option showing correct sequence of different steps.
a. The digestive juices break down the food into simpler substances.
b. Remaining water is absorbed.
c. Food is chewed and mixed with saliva.
d. Most nutrients are absorbed into the blood.

A c → b → a → d
B c → a → d → b
C a → c → d → b
D a → b → c → d

Find the area of the shaded region in the adjoining figure.

(A) 324 cm²

(B) 200 cm²

(C) 180 cm²

In a large commercial complex there are four ways to reach the main road. One of the paths has loose soil, the second is laid with a polished granite, the third is laid with bricks and the fourth has cemented gravel surface. It is raining heavily and Suman wants to reach the main road. The path on which she is least likely to slip is

A Loose soil
B Bricks
C Polished granite
D Cemented gravel.

Which of the following objects exerts the maximum pressure on the floor? (All objects have the same mass).

A
B
C
D

Which is the INCORRECT statement for the given figure?


A Sea breeze blows from sea to land during the day.
B During day, land gets heated faster than the sea.
C Warm air above the sea rises up, and cooler air from land rushes to the sea.
D Both A and B