Electronic Science - Online Test
Q1. magnetic moment of a single-turn current loop of aluminium wire of area A,carrying a current I in a wire of diameter d is
Answer : Option B
Explaination / Solution:
The torque experienced by a current carrying coil of N turns placed in a magnetic field.For N =1, Comparing with torque experienced by a electric dipole
Q2. The Wheatstone bridge is balanced for four resistors R1,R2,R3 and R4 with a cell of emf 1.46 V. The cell is now replaced by another cell of emf 1.08 V. To obtain the balance again
Answer : Option D
Explaination / Solution:
The balance point of the Wheatstone’s bridge is determined by the ratio of the resistances. The change in the e m f of the external battery will have no effect on the balance point.
Q3. For diamagnetic materials
Answer : Option B
Explaination / Solution:
No Explaination.
Q4. A bulb in a staircase has two switches, one switch being at the ground floor and the other one at the first floor. The bulb can be turned ON and also can be turned OFF by any one of the switches irrespective of the state of the other switch. The logic of switching of the bulb resembles
Answer : Option C
Explaination / Solution:
No Explaination.
Q5. Which of the following is not a semiconductor?
Answer : Option D
Explaination / Solution:
Materials that have the resistance levels between those of a conductor and an insulator are referred to as semiconductors.
They are quite common, found in almost all electronic devices. Good examples of semiconductor materials are germanium, selenium, and silicon.
Radium is a chemical element with symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals.
Q6. 
Consider a stator winding of an alternator with an internal high-resistance ground fault. The currents under the fault condition are as shown in the figure. The winding is protected using a differential current scheme with current transformers of ratio 400/5 A as shown. The current through the operating coil is
Answer : Option C
Explaination / Solution:
No Explaination.
Q7. Capacitance is defined as
Answer : Option A
Explaination / Solution:
Capacitance of any conductor is defined as the ratio of the charge given to the conductor to the potential developed in conductor.C=Q/V
Q8. 
Consider the following circuit which uses a 2-to-1 multiplexer as shown in the figure below. The Boolean expression for output F in terms of A and B is
Answer : Option D
Explaination / Solution:
Q9. Consider the Op-Amp circuit shown in the figure. 
If 
then the minimum and maximum
values of ϕ (in radians) are respectively
then the minimum and maximum
values of ϕ (in radians) are respectively
Answer : Option C
Explaination / Solution:
Q10. 
The above synchronous sequential circuit built using JK flip-flops is initialized with
Q2Q1Q0 = 000. The state sequence for this circuit for the next 3 clock cycles is
Answer : Option C
Explaination / Solution:
