Challenge your understanding of fundamental concepts in electricity and magnetism with these medium-difficulty questions, covering topics like Ohm’s Law, circuits, magnetic fields, and electrical induction. This quiz is ideal for students and enthusiasts aiming to assess and reinforce their knowledge in core physics concepts related to electric and magnetic phenomena.
If a resistor has a resistance of 10 ohms and a current of 2 amperes flows through it, what is the voltage across the resistor according to Ohm's Law?
Explanation: According to Ohm's Law, voltage equals current multiplied by resistance, so 2 amperes × 10 ohms = 20 volts. '12 volts' results from adding the numbers instead of multiplying. '8 volts' is from incorrect multiplication (perhaps 4 × 2). '5 volts' is the result of dividing instead of multiplying. Only '20 volts' matches the correct calculation.
In a series circuit with three identical light bulbs, what happens to the brightness of the bulbs if one bulb burns out?
Explanation: In a series circuit, all devices are connected along a single path, so if one bulb burns out and the circuit is broken, electricity cannot flow and all bulbs go out. 'All bulbs become brighter' is incorrect because an open circuit prevents current entirely. 'The remaining bulbs stay lit' or only the burned one turns off would be correct for a parallel circuit, not a series.
According to the right-hand rule, what is the direction of the magnetic field around a straight current-carrying wire if the current flows upward?
Explanation: The right-hand rule states that if you point your thumb in the direction of current (upward), your fingers curl counterclockwise around the wire indicating the magnetic field direction. 'Radially outward' and 'directly downward' don't describe the field; the field forms circles, not lines. 'Clockwise loops' would be correct if the current was downward, not upward.
Which of the following best describes what happens when a magnet is quickly pushed into a coil of wire connected to a sensitive ammeter?
Explanation: A moving magnet near a coil induces a momentary current due to electromagnetic induction; this current exists only while the magnet is moving relative to the coil. 'No current' is wrong as induction definitely occurs. 'A steady current flows' misrepresents the effect; stationary magnets don't induce current. 'Continuous heating' is not a typical result in this basic scenario.
A household fan operates at 120 volts and draws 0.5 amperes of current. What is the power consumption of the fan?
Explanation: Power is calculated using P = V × I, so 120 volts × 0.5 amperes = 60 watts. '0.6 watts' is a decimal error. '240 watts' comes from mistakenly multiplying 120 by 2 or confusing amps with volts. '60 kilowatts' drastically overstates the power; kilowatts are used for much larger loads. '60 watts' is the only correct answer.