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I, II, III and IV are four transparent sheets of equal thickness and made of different materials. A light ray propagates through them as shown in the given figure. The order of speed of light in the four sheets is


AI = III < IV < II
BI = III > IV > II
CI = IV < III < II
DI = III > II > IV.

Nidhi connected two bulbs across two cells in a simple circuit as shown. How can she make the bulbs glow dimmer ?


AReplace one cell with a piece of chalk
BReplace one cell with a piece of wire
CReplace one bulb with a piece of wire
DReplace one bulb with another cell.

Study the given relationship.

Select the option which correctly satisfies the same relationship.

AQuartzite : Basalt : Pumice
BConglomerate : Slate : Shale
CPumice : Shale : Gneiss
DLimestone : Quartzite : Obsidian

Refer to the given passage and answer the following questions. Two concrete rectangular blocks 1 and 2 have dimensions as shown in figures. Standing on one of its faces as shown, the pressure exerted by block 1 is P. Both the blocks are made of same material.

Find the value of P, if weight of the block 1 is 5 N, and the value of x, y and z are 2 cm, 6 cm and 8 cm respectively.

A3125 N m^-2
B4167 N m^-2
C1389 N m^-2
D1042 N m^-2

Which of the following types of houses is most commonly used by nomads?

A
B
C
DNone of these

Select the correct statement.

AUranus is the second largest planet in the solar system.
BNeptune takes about 165 Earth years to orbit around the Sun.
CThe distinguishing feature of Venus is the 'Great Red Spot' on its surface.
DMercury is the hottest planet in the solar system.

Abhay conducted an experiment to observe the variation of temperature with time in water. For that he took two identical set-ups each consisting of a container filled with water, an electric heater and a thermometer. Only the positions of the electric heater and the thermometer differ in both the set-ups.

Which of the following graphs represents the approximate variations of the readings of the thermometers, P and Q with time?

A
B
C
D

Select the correct option for energy changes taking place with respect to given figure.


ALight energy → Mechanical energy → Kinetic energy
BLight energy → Chemical energy → Kinetic energy
CChemical energy → Light energy → Kinetic energy
DMechanical energy → Kinetic energy → Light energy

In the given food web, a decrease in frog population is likely to cause

1. Increase in the grasshopper population.
2. Decrease in the snake population.
3. Increase in the lizard population.

A1 only
B2 and 3 only
C3 only
D1, 2 and 3

Refer to the given figure and select the option with atleast two correct descriptions.


AQ - Receives sperm, R - Site of embryo development
BP - Site of ova formation, R - Site of embryo development
CQ - Site of embryo development, S - Receives sperm
DP - Site of gamete formation, Q - Receives sperm