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Electrical Engineering Questions
Q1. The energy stored in the magnetic field in a solenoid of length 30cm and diameter 3cm wound with 1000 turns of wire & carrying a current of 10A is
- 0.015 joules.
- 0.15 joules.
- 0.5 joules.
- 1.15 joules
Q2. A network is said to be linear, if and only if
- a) The response is proportional to the excitation function.
- b) The principle of superposition applies.
- c)The principle of homogeneity applies.
- d) The principles of superposition and homogeneity apply.
Q3. Kirchoff's law fails in the case of
- a) Non-linear networks.
- b) Linear networks.
- c)Dual networks.
- d) Distributed parameter networks
Q4. In a four branch parallel circuit, 50mA current flows in each branch. If one of the branches opens, the current in other branches
- a) Increase, but not double.
- b) Decrease.
- c) Unaffected.
- d) Double.
Q5. The wave length of a wave in a waveguide is
- a) is greater than in free space
- b) depends only on the waveguide dimensions and the free-space wavelength
- c) is inversely proportional to the phase velocity
- d) is directly proportional to the group velocity
Q6. Characteristic impedance of a quarter wave transformer connected in between a load of 100 ohm and a transmission line of characteristic
impedance 225 ohms is
- a) 100 ohm
- b) 225 ohm
- c) 600 ohm
- d) 150 ohm
Q7. A transverse electromagnetic wave with circular polarization is received by a dipole antenna due to polarization mismatch. The power transfer efficiency from the wave to the antenna is reduced to about
- a) 50%
- b) 35.5%
- c) 25%
- d) 0%
Q8. The unit of displacement density of a magnetic circuit is
- a) Coulomb/ metre
- b) Coulomb / sq. metre
- c) Newton - cm
- d) Amp/ metre
Q9. The derivative of an ideal step function is
- a) an impulse function
- b) zero
- c) sine function
- d) undefined
Q10. An impulse function consists of
- a) entire frequency range with same relative phase
- b) infinite bandwidth with linear phase variation
- C) pure DC
- d) large DC with weak harmonics
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Also Read - Electrical engineering Important Questions Practice For HPCL | GATE | ISRO | BARC | UPSC-ESE | UPPSC
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Q11. The discrete time system described by y(n) = x(n>) is
- a) causal, linear and time varying
- b) causal, nonlinear and time varying
- c)non-causal, linear and time invariant
- d) non-causal, non linear and time variant
Q12. What does the transfer function of a system describe for the system?
- a) only zero input response
- b) only zero state response
- c) both zero input and zero state response
- d) neither zero input response nor zero state response
Q13. Which of the following measures cannot be effective in reducing the noise?
- a) reduction in signaling rate
- b) increase in transmitted power
- c) increase in chanhel bandwidth
- d) use of redundancy
Q14. Which among the following type of transformer have smallest size with same electrical specification ?
- a) ONAN type transformer.
- b) Dry type transformer.
- c) ONAF type transformer.
- d) OFWF type transformer.
Q15. Two transformers operating in parallel will share the load depending upon their
- a) Ratings.
- b) Leakage reactance.
- c) Efficiency.
- d) Per unit impendence.
Q16. Transformer core is laminated,
- a) because it is difficult to fabricate solid core.
- b) because laminated core provides high flux density.
- c) to avoid eddy current and hysteresis losses.
- d) to increase the main flux.
Q17. The eddy current losses in the transformer will be reduced if ?
- a) The laminations are thick.
- b) Number of turns in the primary winding is reduced.
- c) The number of turns in the secondary winding is reduced.
- d) The laminations are thin.
Q18. The Buchholz relay is used to protect the?
- a) Alternators against all internal faults
- b) Oil immersed transformers against all internal faults.
- c) Synchronous motors against all internal faults.
- d) Transmission lines against all short circuit faults.
Q19. Why are transformer stamping annealed before being used for the
building?
- a) to reduce eddy-Current loss due to burning
- b) to reduce hysteresis loss due to burning
- C) to give mecnanical strength to the core
- d) to increase core permeability
