Consider the following statements and select the correct code.
Assertion (A): A diamond sparkles more than a glass imitation cut to the same shape.
Reason (R): The refractive index of diamond is less than that of glass.
The resistance of a conductor is 5 ohm at 50°C and 6 ohm at 100°C. Its resistance at 0°C is
The temperature of an open room volume 30 m3 increases from 17°C to 27°C due to sunshine. The atmospheric pressure in the room remains 1 × 105 Pa. If ni and nf are the number of molecules in the room before and after heating, then nf – ni will be :-
Rainbow is formed due to a combination of
A liquid drop tends to assume a spherical shape because of
Radiocarbon is produced in the atmosphere as a result of
Of the following properties of a wave, the one that is independent of the other is its
Two spheres of same size are made of the same metal but one is hollow and the other is solid. They are heated to same temperature, then
Two equal forces (P each) act at a point inclined to each other at an angle of 120°. The magnitude of their resultant is _______.
A body of mass m = 10–2 kg is moving in a medium and experiences a frictional force F = –kv2. Its intial speed is v0 = 10 ms–1. If, after 10 s, its energy is 1 2 mv0 , the value of k will be:-
Consider the following statements and select the correct code.
Assertion (A): In our houses, the current in A.C. electricity line changes direction 60 times per second.
Reason (R): The frequency of alternating voltage supplied is 50 Hz.
The earth’s gravity acts on both the spacecraft and the bodies in it, giving each?
If the value of gravitational acceleration at a height h above the Earth’s surface is the same as that at a depth d below the Earth’s surface (with both h and d small compared to the Earth’s radius R), then
A wire of 50 cm long and 1 mm² in cross-sectional area carries a current 4A when connected to a 2V battery. The resistivity of the wire is
Harry Brearley has invented
Sound travels with a different speed in media. In what order does the velocity of sound increase in these media?
A : At high altitude regions the cooking of food becomes difficult.
B : Water boils at lower temperature when the pressure is low.
The leaning tower of Pisa does not fall because
Three resistors are connected to form the sides of a triangle ABC, the resistance of the sides AB, BC and CA are 40 ohms; 60 ohms and 100 ohms respectively. The effective resistance between the points A and B in ohms will be
If a rock is brought from the surface of the moon to the earth, then
The weight of a body is not a fixed quantity. It depends upon the location as well as upon?
Of the following natural phenomena, tell which one known in Sanskrit as 'deer's thirst'?
What is unit of Astronomical distance ?
Which of the following is an electromagnetic wave ?
Pendulum clocks become slow in summer because
A uniform resistance wire of length L and diameter d has a resistance R. Another wire of same material has length 4L and diameter 2d, the resistance will be
In a coil of resistance 100 , a current is induced by changing the magnetic flux through it as shown in the figure. The magnitude of change in flux through the coil is : 10 Current (amp.) sec Time 0.5