The core of a transformer is laminated because :-
- ratio of voltage in primary and secondary may be increased
- energy losses due to eddy currents may be minimised
- the weight of the transformer may be reduced
- rusting of the core may be prevented.
The Correct Option is B
Solution and Explanation
The core of a transformer is laminated to minimize the energy losses from eddy currents. This reduces the interference of the primary coil with the secondary coil and thus, the energy transfer becomes efficient. When the transformer core heats up, the energy is lost due to the eddy currents. This is electrical energy given up in the form of heat. To prevent this, the transformer core is laminated.
Also Read: Power Transformers
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In the circuit shown, the identical transistors Q1 and Q2 are biased in the active region with \( \beta = 120 \). The Zener diode is in the breakdown region with \( V_Z = 5 \, V \) and \( I_Z = 25 \, mA \). If \( I_L = 12 \, mA \) and \( V_{EB1} = V_{EB2} = 0.7 \, V \), then the values of \( R_1 \) and \( R_2 \) (in \( k\Omega \), rounded off to one decimal place) are _________, respectively.
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- What is the fate of a piece of DNA carrying only gene of interest which is transfered in to an alien organism?
A. The piece of DNA would be able to multiply itself independently in the progeny cells of the organism.
B. It may get integrated into the genome of the recipient.
C. It may multiple and be inherited along with the host DNA.
D. The alien piece of DNA is not an integral part of chromasame.
E. It shows ability to replicate.
Choose the correct answer from the options given below:
Concepts Used:
Transistors
Transistor
A transistor is a type of semiconductor device that can be used to both conduct and insulate electric current or voltage. A transistor basically acts as a switch and an amplifier. In simple words, we can say that a transistor is a miniature device that is used to control or regulate the flow of electronic signals.
Parts of a Transistor:
A transistor is a combination of three terminals made of semiconducting materials that help in making a connection to an external circuit and allow current to flow. The three terminals are:
- Base: The base activates the transistor. It is thin and lightly doped. It is put in the centre of the transistor.
- Emitter: The emitter is the negative terminal of the transistor. It is heavily doped and is moderately sized.
- Collector: The collector is the negative terminal of the transistor. It is located on the right side of a transistor and is moderately doped. It is larger than the emitter.
Read More: Difference Between NPN and PNP Transistor
Types of Transistors:
A transistor is a type of electronic device which is formed by p-type and n-type semiconductors.
NPN Transistor
- NPN transistor is a type of Bipolar Junction Transistor.
- In this, electrons are major current carriers, and minor ones are holes.
- Their arrangement is in such a way that N-type doped semiconductors are separated by the layer of P-type doped semiconductors which is a thin layer of material embedded between them.
- Emitter Current = Collector Current + Base Current
PNP Transistor
- PNP transistor is also a type of Bipolar Junction Transistor.
- In these, holes are the major source that carries current, and electrons are minor.
- Their arrangement is in a way that P-type doped semiconductor is separated by N-type doped semiconductor material which is a thin layer.
- Emitter Current = Collector Current + Base Current
Read More: Characteristics of a Transistor
Configurations of a Transistor:
Using the three types of configuration can be used to design any transistor circuit. The three types of configuration of a transistor are:
- Common Emitter Transistor
- Common Base Transistor
- Common Collector Transistor
Common Emitter (CE) Configuration of a Transistor
In Common Emitter Configuration, the transistor’s emitter terminal will be connected common between the output terminal and the input terminal.
Input Characteristics
- Variation of emitter current (IB) with Base-Emitter voltage (VBE) when Collector-Emitter voltage (VCE) is held constant.
- Rin = ΔVBE/ΔIB | VCE = Constant
Output Characteristics
- Variation of collector current (IC) with Collector-Emitter voltage (VCE) when the base current (IB) is held constant.
- Rout = ΔVCE/ΔIC | IB = Constant
Current Transfer Characteristics
- The variation of the collector current (IC) with the base current (IB) when the collector-emitter voltage (VCE) is constant.
- α = ΔIC/ΔIB | VCB = Constant
Common Base (CB) Configuration of a Transistor
In Common Base Configuration, the transistor’s base terminal will be connected common between the output terminal and the input terminal.
Input Characteristics
- Variation of emitter current (IE) with Base-Emitter voltage (VBE) when the Collector Base voltage (VCB) is held constant.
- Rin = ΔVBE/ΔIE | VCB = Constant
Output Characteristics
- Variation of collector current (IC) with Collector-Base voltage (VCB) when the emitter current (IE) is held constant.
- Rout = ΔVCB/ΔIB | IE = Constant
Current Transfer Characteristics
- The variation of the collector current (IC) with the emitter current (IE) when the Collector Base voltage (VCB) is constant.
- α = ΔIC/ΔIE | VCB = Constant
Common Collector Configuration of a Transistor
In Common Collector Configuration, the transistor’s collector terminal will be connected common between the output terminal and the input terminal.
Input Characteristics
- Variation of emitter current (IB) with Collector-Base voltage (VCB) when the Collector Base voltage (VCB) is held constant.
Output Characteristics
- Variation of emitter current (IE) with Collector-Emitter voltage (VCE) when the base current (IB) is held constant.
Current Transfer Characteristics
- The variation of the collector current (IE) with the base current (IB) when the Collector-Emitter voltage (VCE) is constant.