1. The Vernier constant of Vernier calipers is 0.1 mm and it has zero error of (-0.05) cm. White measuring diameter of a sphere, the main scale reading is 1.7 cm and coinciding vernier division is 5. The correct diameter will be 10-2 cm. 2. 3. A small spherical ball of radius 0.1mm and density 104kgm falls freely under gravity through a distance h before entering a tank of water. If, after entering the water the velocity inside water, then the value of h will be m. (Given g = 10 ms-2, viscosity of water = 1.0 10-5 N-sm-2). In an experiment to determine the velocity of sound in air at room temperature using a resonance tube, the first resonance is observed when the air column has a length of 20.0 cm for a tuning form of frequency 400 Hz is used. The velocity of the sound at room temperature is 336 ms. The third resonance is observed when the air column has a length of cm. 4. V. Two resistors are connected in series across a battery as shown in figure. If a voltmeter of resistance 2000 2 is used to measure the potential difference across 5000 resister, the reading of the voltmeter will be 500 6000 www. www. 20 V 5. A potential barrier of 0.4V exists across a p-n junction. An electron enters the junction from the n-side with a speed of 6.0 105. The speed with which electron enters the p side will be 3 x105ms the value of x is (Given mass of electron = 9 10-31 kg, charge on electron = 1.6 10-19 C.)