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Questions in physics

[Done] A point charge of 5.0 × 10⁻⁷ C moves to the right at 2.6 × 10⁵ m/s in a magnetic field that is directed into the screen and has a field strength of 1.8 × 10⁻² T. What is the magnitude of the magnetic force acting on the charge? Options: 0 N 2.3 × 10⁻³ N 23 N 2.3 × 10¹¹ N

[Done] 2. Major part of electric current in an intrinsic semiconductor is due to drift of (a) conduction-band electrons (b) valence-band electrons (c) conduction-band holes (d) valence-band holes (e) None of the above. 3. The rms value of current in a full-wave rectifier is given as (a) [tex]$I_m / \pi$[/tex] (b) [tex]$I_m / 2$[/tex] (c) [tex]$I_m / \sqrt{ } 2$[/tex] (d) [tex]$2 l_m / \pi$[/tex]

[Done] Which of the following statements about nuclear energy is true? A. Nuclear energy cannot be contained nor controlled B. Nuclear energy is contained in nuclear bonds C. Nuclear energy is less efficient than other energy forms D. All of the above are true

[Done] A quarterback throws a football toward a receiver from a height of 6 ft. The initial vertical velocity of the ball is [tex]$14 ft/s$[/tex]. At the same time that the ball is thrown, the receiver raises his hands to a height of 8 ft and jumps up with an initial vertical velocity of [tex]$10 ft/s$[/tex]. Projectile motion formula: [tex] \begin{array}{l} h=-16 t^2+v t+h_0 \\ t=\text { time, in seconds, since the ball was thrown } \\ h=\text { height, in feet, above the ground } \end{array} [/tex] Complete the system that models the heights of the ball and the receiver's hands over time. [tex] \begin{array}{l} h=-16 t^2+14 t+6 \\ h=-16 t^2+10 t+8 \end{array} [/tex] After [ ] seconds, the receiver's hands and the ball will be at the same height. The receiver's hands and the ball are at the same height at [ ] ft above the ground.

[Done] 1. A cylindrical magnet has only one pole. 2. Artificial magnets were discovered in Greece. 3. Similar poles of a magnet repel each other. 4. Maximum iron filings stick in the middle of a bar magnet when it is brought near them.

[Done] Select the correct answer. The pressure applied on any object can be calculated by using the following equation: [tex]$P=\frac{F}{A}$[/tex] In the pressure equation, [tex]$P$[/tex] represents the pressure on the object in pascals ([tex]$Pa$[/tex]), [tex]$F$[/tex] represents the force applied on the object in newtons ([tex]$N$[/tex]), and [tex]$A$[/tex] represents the area, in square meters, of the object over which the pressure is applied. What is the pressure applied inside a container having an inner area of 16 square meters over which a force of 1,306 newtons is applied? Note: Answers should be rounded to the nearest whole unit. A. 245 Pa B. 163 Pa C. 41 Pa D. 82 Pa

[Done] Abhimanyu rolled an electric cell from a certain point on an inclined wooden board; it travels some distance on Floor A. He then took the same electric cell and rolled it from the same point on the same inclined board on Floor B. His results are summarized in the table below. | Floor | Distance travelled | |---|---| | Floor A | 35 cm | | Floor B | 20 cm | a. Identify the type of friction acting in both cases. b. Which floor offers greater friction? Give reason for your answer.

[Done] 1. Which one of the following is a correct statement about temperature? a. It is a measure of how warm an object is. b. It is a measure of how hot or cold an object is. c. It is a measure of how heavy an object is. d. None of these 2. In which of the following thermometers is a kink used? a. Digital thermometers b. Infra-red thermometers c. Mercury-based thermometer d. None of these 3. Which of the following in degree Celsius is equivalent to 32°F? a. 100°C b. 10°C c. 0°C d. 1°C 4. Sukanya and Diya measured their body temperatures. Sukanya found it to be 98.6°F, while Diya's body temp was 37°C. Which of the following statements is true? a. Sukanya has a higher body temperature than Diya. b. Diya has a lower body temperature than Sukanya. c. Sukanya and Diya both have normal body temperature. d. Sukanya is suffering from fever.

[Done] Convert 32 degrees Fahrenheit to degrees Celsius. A. $10^{\circ} C$ B. $-10^{\circ} C$ C. $20^{\circ} C$ D. $0^{\circ} C$

[Done] Hot sticks are used to discharge capacitors. A. True B. False