MCQ
upsc-p1-science-tech-physics-applications MCQ - Practice Questions with Answers
Solve 10 upsc-p1-science-tech-physics-applications questions for RAS/RPSC preparation.
Practice questions
Q1With reference to electric power systems, consider the following statements: 1. An ordinary transformer can step up steady direct current. 2. For the same transmitted power, raising voltage reduces current and resistive line loss. 3. Household appliances are generally connected in parallel so that each receives the rated voltage and can be switched independently. Select the correct answer using the code given below.
Statements 2 and 3 are correct. A transformer requires changing magnetic flux and therefore cannot step up steady DC in ordinary transformer action. At fixed power, higher transmission voltage lowers current and hence I-squared-R loss; parallel household wiring provides rated voltage and independent switching.
Q2Match List I with List II and select the correct answer using the code given below: List I (a) Earthing (b) Fuse or MCB (c) RCCB (d) Parallel household wiring List II 1. Detects leakage-current imbalance 2. Gives leakage current a low-resistance path 3. Allows appliances to receive rated voltage and be switched independently 4. Interrupts an overcurrent
Earthing provides a low-resistance leakage path; a fuse or MCB interrupts excess current; an RCCB responds to leakage imbalance; and parallel wiring gives each appliance rated voltage and independent switching. Therefore option D gives the complete correct matching.
Q3With reference to heat and thermodynamics, consider the following statements: 1. During a phase change, heat may be absorbed while temperature remains constant. 2. A refrigerator moves heat from a colder region to a hotter region without external work. 3. Black surfaces are good absorbers as well as good emitters of radiant heat. Select the correct answer using the code given below.
Statements 1 and 3 are correct. Latent heat allows energy transfer during a change of state without an immediate temperature change. Moving heat from cold to hot requires external work, so Statement 2 violates the stated direction of the second law.
Q4With reference to electromagnetic radiation, consider the following statements: 1. All electromagnetic waves travel at the same speed in vacuum. 2. Ordinary visible light has enough photon energy to ionise atoms. 3. X-rays and gamma rays are ionising radiation. Select the correct answer using the code given below.
Statements 1 and 3 are correct. Electromagnetic waves share the speed of light in vacuum but differ in frequency, wavelength and photon energy. Ordinary visible light is non-ionising, whereas X-rays and gamma rays can ionise matter.
Q5With reference to measurement, consider the following statements: 1. A set of repeatedly identical but wrong readings can be precise without being accurate. 2. A digital meter displaying more decimal places is necessarily accurate. 3. Calibration links an instrument to a trusted standard. Select the correct answer using the code given below.
Statements 1 and 3 are correct. Precision concerns repeatability, whereas accuracy concerns closeness to the true value. More displayed decimals do not cure poor calibration, so Statement 2 is incorrect.
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6Match List I with List II and select the correct answer using the code given below: List I (a) Archimedes' principle (b) Pascal's law (c) High specific heat capacity of water (d) Rayleigh scattering List II 1. Hydraulic brakes 2. Moderation of coastal climate 3. Blue colour of the sky 4. Changing a submarine's effective density with ballast tanks
7Consider the following statements: 1. SONAR uses sound in seawater because sound travels well there while electromagnetic waves attenuate strongly. 2. Radio communication with satellites uses electromagnetic waves, not sound. Select the correct answer using the code given below.
8Arrange the following electromagnetic waves in increasing order of frequency: (a) Visible light (b) Radio waves (c) Infrared (d) Microwaves Select the correct answer using the code given below.
9Arrange the following developments in chronological order from earliest to latest: (a) Aditya-L1 entered halo orbit around Sun-Earth L1 (b) The Union Cabinet approved the National Quantum Mission (c) SpaDeX completed docking (d) Chandrayaan-3 soft-landed on the Moon Select the correct answer using the code given below.
10Consider the following statements: 1. A convex lens can correct hypermetropia. 2. Increasing magnification necessarily increases resolution. Select the correct answer using the code given below.