Physics Test - ...

A monochromatic light source of wavelength λ is placed at S. Three slits S₁, S₂ and S₃ are equidistant from the source S and the point P on the screen. S₁P-S₂P=λ/6 and S₁P-S₃P = 2λ/3. If I be the intensity at P when only one slit is open, the intensity at P when all the three slits are open is

A luminous point object is moving along the principal axis of a concave mirror of focal length 12 cm towards it. When its distance from the mirror is 20 cm its velocity is 4 cm/s. The velocity of the image in cm/s at that instant.

An ammeter is designed by shunting a 60 Ω galvanometer with a 60 Ω resistance. The additional shunt that should be connected across it to double the range is

Two blocks P and Q are connected by a light inextensible string passing over a smooth pulley fixed as shown in the Figure. The coefficient of friction of blocks P and Q to the table is μ = 0.3; the mass of the block Q is 20 kg. The mass of the block P for the block just to slip is

One million small identical drops of water, all charged to the same potential, are combined to form a single large drop. If E is the sum of the electrostatic energy of each small drop, the combined energy of the large drop is

A square lead slab of side a = 50 cm and thickness t = 0.5 cm is subjected to a shearing force of magnitude F = 9 × 10⁴ N. If the shear modulus of lead is η = 5.6 × 10⁹ Pa, then how much work is done by the force?

E, m, p and G denote energy, mass, angular momentum and gravitational constant. Then $\frac{E{p}^2}{m^5{G}^2}$has the dimensions of

Consider telecommunication through optical fibres. Which of the following statements is NOT true?

The number of AM broadcast stations that can be accommodated at a 150 kHz band width, if the highest frequency modulating carrier is 5 kHz is

The frequency of turning forks X and Y are respectively 15% more and 8% less than the frequency of turning fork Z. When X and Y are simultaneously excited, 45 beats per second are produced. Find the frequency of turning fork X is