Question 1

Consider the following: 1. Bluetooth device 2. Cordless phone 3. Microwave oven 4. Wi-Fi device. Which of the above can operate between 2.4 and 2.5 GHz range of radio frequency band?

Accepted Answer

Microwaves are a form of electromagnetic radiation that have wavelengths varying from one meter to one millimeter, or frequencies between 300 MHz (0.3 GHz) and 300 GHz. Microwave ovens emit nonionizing microwave radiation at a frequency around 2.45 GHz to heat food through absorption of energy by water, fats, and sugars in the food. Bluetooth and Wi-Fi technologies are commonly used for networking, printing, and file transfer, operating within the 2.4 to 2.5 GHz frequency range. In the United States, cordless phones typically utilize the 1.9 GHz or 2.4 GHz frequency bands.

Question 2

Assertion (A): Transformer is useful for stepping up or stepping down voltages. Reason (R): Transformer is a device used in D.C. circuits.

Accepted Answer

A transformer is a device that is beneficial for increasing or decreasing voltages. It is used in AC circuits, not DC circuits. The correct option is (c) where A is true but R is false.

Question 3

Domestic electrical wiring is basically a:

Accepted Answer

In domestic electrical wiring, the most common type of connection used is parallel connection. This means that the voltage across each device or appliance remains constant, and the total current flowing through the circuit is the combined sum of the currents passing through each individual component.

Question 4

Assertion (A): In our houses, the current in A.C. electricity line changes direction 60 times per second. Reason (R): The frequency of alternating voltage supplied is 50 Hz.

Accepted Answer

In our houses, the flow of current in the AC electricity line switches direction 60 times every second. This is because the frequency of the alternating voltage supplied to our homes is 50 Hz. The correct option is that statement A is false but statement R is true.

Question 5

Fluorescent tubes are fitted with a choke. The choke coil:

Accepted Answer

Fluorescent tubes are equipped with a choke coil, which is responsible for reducing the current in the circuit.

Physics - Electricity & Magnetism — UPSC Previous Year Questions

Consider the following: 1. Bluetooth device 2. Cordless phone 3. Microwave oven 4. Wi-Fi device. Which of the above can operate between 2.4 and 2.5 GHz range of radio frequency band?

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Sample Questions

Physics - Electricity & Magnetism — UPSC Previous Year Questions

Consider the following: 1. Bluetooth device 2. Cordless phone 3. Microwave oven 4. Wi-Fi device. Which of the above can operate between 2.4 and 2.5 GHz range of radio frequency band?

Year-wise Distribution

Sample Questions