MHT CET · Physics · Alternating Current
A step-down transformer has \(N_{\mathrm{S}}\) to \(N_{\mathrm{p}}\) ratio of \(20: 1\). If \(8 \mathrm{~V}\) are developed across \(0.4 \Omega\) secondary, the primary current will be
- A \(1 \mathrm{~A}\)
- B \(0.5 \mathrm{~A}\)
- C \(4 \mathrm{~A}\)
- D \(2 \mathrm{~A}\)
Answer & Solution
Correct Answer
(A) \(1 \mathrm{~A}\)
Step-by-step Solution
Detailed explanation
For a step-down transformer:
\(\frac{N_{\mathrm{P}}}{N_{\mathrm{S}}}=\frac{20}{1}=\frac{V_p}{V_{\mathrm{s}}}=\frac{I_s}{I_p}\)
\(\begin{aligned} & \therefore I_s=\frac{8 \mathrm{~V}}{0.4 \mathrm{~A}}=20 \mathrm{~A} \\ & \Rightarrow I_p=I_s \times \frac{1}{20}=1 \mathrm{~A}\end{aligned}\)
\(\frac{N_{\mathrm{P}}}{N_{\mathrm{S}}}=\frac{20}{1}=\frac{V_p}{V_{\mathrm{s}}}=\frac{I_s}{I_p}\)
\(\begin{aligned} & \therefore I_s=\frac{8 \mathrm{~V}}{0.4 \mathrm{~A}}=20 \mathrm{~A} \\ & \Rightarrow I_p=I_s \times \frac{1}{20}=1 \mathrm{~A}\end{aligned}\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- Resistor of \(2 \Omega\), inductor of \(100 \mu \mathrm{H}\) and capacitor of \(400 \mathrm{pF}\) are connected in series across an a.c. source of \(e_{r m s}=0.1\) volt. At resonance, voltage drop across inductor isMHT CET 2022 Medium
- The minimum distance between an object and its real image formed by a convex lens of focal length \(f\) isMHT CET 2022 Hard
- A series combination of \(n_1\) capacitors, each of value \(C_1\) is charged by a source of potential difference 6 V . Another parallel combination of \(\mathrm{n}_2\) capacitors, each of value \(\mathrm{C}_2\) is charged by a source of potential' difference 2 V . Total energy of both the combinations is same. The value of \(\mathrm{C}_2\) in terms of \(\mathrm{C}_1\) isMHT CET 2024 Hard
- A piece of semiconductor is connected in series in an electric circuit. On increasing the temperature, the current in the circuit willMHT CET 2025 Easy
- Two bodies A and B move in same straight line starting from same position. Body A moves with constant velocity 'u' and body B moves with constant acceleration ' \(a\) '. When their velocities become equal, the distance between them isMHT CET 2025 Medium
- A parallel combination of three condensers of capacities ' \(2 \mathrm{C}\), ' \(\mathrm{C}\) ' and ' \(\mathrm{C} / 2\) ' is connected
Across \(10 \mathrm{~V}\) battery. All the condensers are fully charged to charges ' \(\mathrm{Q}_1\) ', ' \(\mathrm{Q}_2\) ' and ' \(\mathrm{Q}\) 3' respectively. The ratio \(\mathrm{Q}_1: \mathrm{Q}_2: \mathrm{Q}_3\) isMHT CET 2022 Medium
More PYQs from MHT CET
- Water (of density 'o') flows steadily through a horizontal pipe of variable cross-section. If the pressure of water is 'P' at a point where the flow speed is ' \(V\) ', then the pressure at another point where the flow speed becomes 3 V isMHT CET 2025 Medium
- Which from following equations represents a correct relationship between standard cell potential and equilibrium constant for cell reaction?MHT CET 2024 Easy
- The derivative of \(\tan ^{-1}\left(\frac{\sqrt{1+x^2}-1}{x}\right)\) w.r.t. \(\tan ^{-1}\left(\frac{2 x \sqrt{1-x^2}}{1-2 x^2}\right)\) at \(x=0\) isMHT CET 2025 Medium
- The distance between two consecutive points with phase difference of \(45^{\circ}\) in a wave of frequency 300 Hz is 4.0 m . The velocity of the travelling wave is (in \(\mathrm{km} / \mathrm{s}\) )MHT CET 2025 Medium
- A circular current carrying coil has radius \(\mathrm{R}\). At what distance from the centre of the coil on the axis, the magnetic induction will become \(\frac{1}{8}\) th of its value at the centre of the coil?MHT CET 2020 Hard
- What is "After birth" referred to?MHT CET 2015 Medium