User Forum

Steam at 100°C is a more effective heating agent than water at the same temperature because 1 kg of steam at 100°C has _____ more energy than 1 kg of water at the same temperature.

A40.2 J
B52.5 × 10⁶ J
C22.5 × 10⁵ J
D80.4 J

Read the given statements and select the option that correctly identifies them as true (T) and false (F) ones. (Take sin 28° = 0.47, cos 28° = 0.88, sin 17° = 0.29)
(i) When a ray of light is incident at an angle of 45° on one face of rectangular slab of thickness 10 cm and refractive index 1.5, the lateral shift produced is 3.3 cm.
(ii) The speed of light in a glass of refractive index 1.5 is more than the speed of light in water.
(iii) The focal length of a plane convex lens of refractive index 1.5 and radius of curvature 0.15 m is 0.3 m.
(iv) For a biconvex lens with focal length times of radius of curvature, the refractive index of material of the lens is 1.5.

Names of how many micronutrients required by plants are hidden in the given word grid?


A2
B3
C4
D5

During a war the bomber drops three bombs consecutively, at short and constant intervals, while cruising horizontally at a constant speed. Which one of the given diagrams shows the positions of the three bombs as observed by the pilot right after the last bomb leaves the bomber.(Assume that the air resistance is negligible.)

A
B
C
D

As shown in the given figure, the resistance of all the wires between any two adjacent dots is R. What is the equivalent resistance between X and Y?


A
B
C
D14 R

Aquarium keepers are typically advised to remove dead fish from an aquarium the moment they are discovered. Otherwise, the water may soon become cloudy due to a bacterial bloom. Which of the following best explains why a bacterial bloom should be avoided?

A The bacteria acting on the dead organism may 1 infect other fish and aquatic organisms, causing an aquarium plague.
B The cloudiness in the tank prevents the fish keepers from properly observing their pets.
C The bacteria may become airborne with the evaporation of water from the aquarium and cause diseases in the external environment.
D The sudden spike in bacterial population may result in insufficient dissolved oxygen for the other aquatic organisms, causing more aquatic life to die.

Which of the following crops are rabi crops?

AWheat, Barley, Gram
BRice, Maize, Wheat
CBeans, Jowar, Bajra
DCarrot, Maize, Barley

Match column I with column II and select the correct option from the given codes.


A(i)-(A, B), (ii)-(E), (iii)-(D), (iv)-(C), (v)-(A)
B(i)-(E), (ii)-(C), (iii)-(A, E), (iv)-(C), (v)-(D, E)
C(i)-(C, D), (ii)-(D), (iii)-(A, B), (iv)-(E), (v)-(A)
D(i)-(E), (ii)-(C), (iii)-(A, B, C), (iv)-(E), (v)-(D)

is placed on a plane mirror. A pen is adjusted vertically until its image is seen to be at the same position when viewed from the top as shown.
Given that f is the focal length of the lens, what is the distance between the pen and the optical centre of the lens?


A 0.5 f
B f
C 2 f
D 4 f

Which of the following CANNOT be found in the given crossword?


AA hard rock used for making kitchen counters
BA type of soil which has very fine particles and has very little space for air between its particles
CLightest rock used for polishing teeth by dentists
DA precious mineral used in jewellery