| 1 |
The magnitude of potential barrier for Ge is |
0.7 v
0.3 V
7v
3 v
|
| 2 |
A pulsating DC can be converted into constant voltage by using |
Filter
Full wave rectifier
Half wave rectifie
Bridge rectifier
|
| 3 |
In a full wave rectifier with input frequency 50Hz. The frequency of pulsating D)C)
received as an output across the load is |
50 Hz
100 Hz
500 Hz
zero
|
| 4 |
The power output of a full wave rectifier is: |
Equal to H.W.R
Twice of H.W.R
Half of H.W.R
Four times of H.W.R
|
| 5 |
In a full wave rectifier: |
DC current is twice that of half wave rectifier
DC pulses are twice per cycle that of half wave rectifier
DC voltage is twice that of half wave rectifier
All are correct
|
| 6 |
A circuit that converts Pulsating DC into smooth DC contain : |
Filter
Capacitor
Inductor
LC circuit
|
| 7 |
The efficiency of full wave rectifier is: |
25.6%
81.2%
81.6%
71.2%
|
| 8 |
The efficiency of half wave rectifier is: |
25.6%
1.2%
40.6%
66.6%
|
| 9 |
For a normal AC cycle, during T/2 to T the diode act as: |
Open switch
full wave rectifier
Close switch
All are correct
|
| 10 |
A device which convert DC into AC is calleD) |
Invertor
Generator
Rectifier
Motor
|
| 11 |
A certain noninverting amplifier has R1 of 1 kΩ and R2 of 100 kΩ. The closed-loop voltage
gain is ……… |
100,000
100
1000
101
|
| 12 |
The resistance of operational amplifier between inverting and non-inverting terminal is of
the order of: |
Few Ohms
Mega Ohms
Few Kilo Ohms
Micro Ohms
|
| 13 |
For the same value of resistors the output of non-inverting amplifier compared to the
output of inverting amplifier is, (ignoring phase difference) |
Greater
Equal
Smaller
Undefined
|
| 14 |
A non-inverting amplifier has infinite input resistance then the voltage gain of noninverting amplifier will be: |
Zero
Infinite
One
100
|
| 15 |
A non-conducting semiconductor diode is: |
Forward biased
Poorly biased
Reverse biased
None of them
|
| 16 |
In full wave rectification, the output DC voltage across the load is obtained for. |
The positive half cycle of input AC only
The negative half cycle of input AC
The completes cycle of input AC only
All of the above
|
| 17 |
The magnetic field due to the electric current in a conducting wire is: |
Towards the centre of the conducting wire
Circular around the conducting wire
In the direction of the electric current
In the direction opposite to the electric current
|
| 18 |
The magnetic field of a solenoid is quite similar to that of a: |
Straight conductor
A horse shoe magne
Any magnet
A bar magnet
|
| 19 |
The magnetic field produced due to the current in a straight wire is proportionalto the : |
Electric current
Conducting material
Length of the wire
Diameter of the wire
|
| 20 |
If an electron vertically downwards, then the horizontal component of the earth’s
magnetic field will deflect it to wards |
West
East
North
North
|
| 21 |
A tritium and alpha particle enter the magnetic field with same kinetic energy, what will
be the ratio of their radii? |
3:4
√3: 1
√3: 4
√3:√2
|
| 22 |
An electron and a proton are projected at right angles to a uniform magnetic field with |
the electron trajectory will be less curved than proton’s trajectory
the electron trajectory will be more curved than proton’s trajectory
) both trajectories will be equally curved
) both particles continue to move along a straight lins
|
| 23 |
The direction of force experienced by a moving in a magnetic field will be: |
Parallel to the field
Opposite to the field
Parallel to its direction of motion
Perpendicular to both the field and the velocity vector
|
| 24 |
Charge to mass ratio (e/m) of a charge particle is also called its: |
Specific charge
Specific Force
Gyro-magnetic ratio
Magneto-mechanical ratio
|
| 25 |
A positively charged particle is moving perpendicular to a uniform magnetic field. The
magnetic force makes the particle to move along: |
An elliptical path
A circular path
A parabolic path
None of these
|
| 26 |
Which one of the following particles projected perpendicular to a uniform magnetic field
with the same velocity will be deflected least? |
Electron
Proton
Deuton
None of these
|
| 27 |
A magnetic field |
Always exerts a force on a charged particle
Never exerts a force on a charged particle
Exerts a force on a charged particle if it is moving across the magnetic lines of force
Exerts a force on a charged particle if it is moving along the magnetic lines of force.
|
| 28 |
A straight current carrying conductor experiences maximum forces in a uniform
magnetic field when it is placed: |
Parallel to the field
Perpendicular o the field
At an angle of 45 to the field
None of these
|
| 29 |
A long solenoid has 20 turns/ cm. The current necessary to produce a magnetic field of
20 mellites inside the solenoid is approximately: |
1A
2A
4A
8A
|
| 30 |
Magnetic field inside a solenoid is: |
) Directly proportional to current
Inversely proportional to current
Directly proportional to its length
Inversely proportional to total no of turns
|
| 31 |
A source of a magnetic field is: |
An isolated magnetic
A static electric charge
A moving electric charge
None of these
|
| 32 |
A steady current is flowing in a conductor of non-uniform cross-section.
Thecharge passing through any cross-section per unit time is |
Directly proportional to the area of cross-section
Inversely proportional to the area of cross-section
Proportional to square of the area of cross-section
Independent of the area of cross-section
|
| 33 |
A cell of negligible resistance and e.m.f 2 V is connected across a series
combination of 2,3 and 5 ohms. The p.d. across the 3 Ω resistor is |
0.6 V
1/3 V
2/3 V
4/3 V
|
| 34 |
When resistances are connected in Parallel, the effective resistance will
be |
Product of the reciprocals of the individual resistances
Product of the individual resistances
Sum of the reciprocals of the individual resistances
Sum of the individual resistances
|
| 35 |
Which combination of 7 identical resistors of 3-ohm will give 12/13 ohm: |
3 series, 4 parallel
5 series, 2 parallel
2 series, 5 parallel
4 series, 3 parallel
|
| 36 |
Which of the Following bulb will glow Brightest? |
100W
200W
300W
400W
|
| 37 |
The emf of a cell of negligible internal resistance is 2V. It is connected to the series
combination of 𝟐𝛀, 𝟑𝛀 𝐚𝐧𝐝 𝟓𝛀 resistance. The potential difference across 𝟑𝛀 resistance will be
in volt: |
0.6
2/3
3
6
|
| 38 |
A 100W, 220V bulb is operated on a 110V line, the power consumed is: |
25W
75W
50W
100W
|
| 39 |
Resistance of 60 watt bulbs in 120V line is: |
20 ohms
240 ohms
0.15 ohms
180 ohms
|
| 40 |
If a source of emf is traversed from positive to negative the potential change will be: |
Positive
Negative
Zero
Constant
|