Physics Test - ...

A working transistor with its three legs marked P, Q and R is tested using a multimeter. No conduction is found between P and Q. By connecting the common (negative) terminal of themultimeter to R and the other (positive) terminal to P or Q, some resistance is seen on themultimeter. Which of the following is true for the transistor?

The transition from the state n = 4 to n = 3 in a hydrogen like atom results in ultraviolet radiation. Infrared radiation will be obtained in the transition from

A parallel plate capacitor with air between the plates has a capacitance of 9 pF. The separationbetween its plates is ‘d’. The space between the plates is now filled with two dielectrics. One of the dielectrics has dielectric constant k1 = 3 and thickness d/3 while the other one has dielectric constant k2 = 6 and thickness 2d/3 . Capacitance of the capacitor is now

This question contains Statement-1 and Statement-2. Of the four choices given after the statements, choose the one that best describes the two statements.Statement-1: The temperature dependence of resistance is usually given as R = Ro(1 + α∆t). The resistance of a wire changes from 100 Ω to 150 Ω when its temperature is increased from 27 deg C to 227 deg C. This implies that α= 2.5 x 10^-3 / deg C.Statement 2: R = Ri (1 + α∆T) is valid only when the change in the temperature ∆T is small and ∆R = (R - Ro) << Ro.

Directions: Two moles of helium gas are taken over the cycle ABCDA, as shown in the P – T diagram. Question : Assuming the gas to be ideal the work done on the gas in taking it from A to B is

A body of mass m = 3.513 kg is moving along the x-axis with a speed of 5.00 ms^−1. The magnitude of its momentum is recorded as

A charge Q is placed at each of the opposite corners of a square. A charge q is placed at each of the other two corners. If the net electrical force on Q is zero, then the Q/q equals

Wave property of electrons implies that they will show diffraction effects. Davisson and Germer demonstrated this by diffracting electrons from crystals. The law governing the diffraction from a crystal is obtained by requiring that electron waves reflected from the planes of atoms in a crystal interfere constructively (see in figure). Que: Electrons accelerated by potential V are diffracted from a crystal. If d = 1Å and i = 30°, V should be about (h = 6.6 × 10^−34 Js, me = 9.1 × 10^−31 kg, e = 1.6 × 10^−19 C)

An experiment is performed to find the refractive index of glass using a travelling microscope. In this experiment distance are measured by