Acurrent i flows through a uniform wire of dimater d , when the mean drift velocity is v . the same current flow through the wire of dimater d/2 made up of same material the mean drift velocity of electron is?

. A positive charge, Q, is located in a magnetic field, B, which is directed toward the right, as shown in the figure above. If Q travels toward the top of the page, the direction of the magnetic force on Q is a. toward the right. c. away from you, into the page. b. toward you, out of the page. d. There is no magnetic force. 12. Which conversion process is the basic function of the electric motor? a. mechanical energy to electrical energy b. electrical energy to mechanical energy c. low voltage to high voltage, or vice versa d. alternating current to direct current 13. There are four coils of wire being used as electromagnets. They all have the same size and are made up of the same material but have a different number of loops. Which coil will produce the weakest magnetic field when the same amount of current passes through all of the coils? a. a coil having 10 loops c. a coil having 30 loops b. a coil having 25 loops d. a coil having 45 loops 14. A/An is a long coil of wire with many loops used to create a large magnetic field. a. solenoid c. electric motor b. electromagnet d. armature 15. A/An is described as the area around a magnet where other magnets would be accelerated. a. magnetic field c. domain b. magnetic flux d. solenoid 16. Which factor will not affect the strength of a solenoid? a. number of wraps c. radius of the wraps b. strength of current d. core type 17. What are the units of electromotive force? a. newtons c. volts b. newtons per coulomb d. volts per ampere 18. The number of turns on the primary coil of a step-down transformer the number of turns on the secondary coil. a. equals c. is less than b. is greater than d. is unrelated to 19. A generator is used to light a bulb. Energy for lighting the bulb actually comes from a. a plug where the generator is connected to the wall. b. a mechanical input to the generator. c. the magnet in the generator. d. the coil of wire. e. none of the above 20. The principal advantage of AC power over DC power is that a. AC voltage oscillates, whereas DC voltage does not. b. lower voltages are used. c. AC circuits multiply power more easily. d. AC voltage can be transformed more easily. e. AC circuits are safer.  

1. Equilibrium temperature = 7.3 C. Change in temperature of water = 2.4 C. Mass of water = 2.5 kg.
Hence energy absorbed = 4186*2.4/2.5 = 25116 J
Energy absorbed = Energy lost by brass.
Change in temperature of brass = 90.1 C. Mass = 0.52 kg. Energy lost = 25116 J
Hence specific heat = 25116/0.52/90.1 = 536 J/kgC

2. Change in temperature = 14 C
Mass of water = 195 g
Heat required to raise 1g water by 1C = 4.18 J
Hence heat required = 4.18*195*14 = 11411.4 J

For the fifth question we need the diagram or experiment above the question for context