Basic Electricity Question & Answer List

Q. Draft velocity of electrons is-

Ans. Very small in comparison to speed of light

Q. Ratio of the voltage and electric current in a closed circuit-

Ans. Remain constant

Q. Condition for the validity under Ohm’s law is that the

Ans. Temperature should remain co

Q. Resistance of a wire always increases if-

Ans. Number of free electrons available become less

Q. The resistance of wire varies inversely as-

Ans. Area of cross-section

Q. For a fixed supply voltage the current flowing through a conductor will increase when its-

Ans. Length is reduced

Q. A wire of length I and of circular cross section of radius r has resistance of R ohms. Another wire of same material and of cross-sectional radius 2r will have the same resistance R if the length is-

Ans. 4l

Q. Two resistance of equal value, when connected in parallel, give an equivalent resistance of R. if these resistors are connected in series , the equivalent resistance will be-

Ans. 4R

Q. The resistance of a parallel circuit consisting of two resistance is 12 . one of the resistance wires breaks and the effective resistance becomes 18 .the resistance of the broken wire is-

Ans. 36

Q. When one leg of a parallel circuit gets opened out, the current drawn from the supply will-

Ans. Reduce

Q. For a series as well as a parallel circuit-

Ans. Powers are additive

Q. A keeper is used for-

Ans. Providing a closed path for the magnetic flux

Q. When a resistance element of a heater gets fused we remove if now 10 W bulb is replaced by a 40 W bulb, the heater output will-

Ans. Decrease

Q. When the voltage applied across an electric iron is halved, the power consumption of the iron will reduce to-

Ans. One-fourth

Q. For a give line voltage, four heating coils will produce maximum heat when connected-

Ans. All in parallel

Q. Two lamps of 200 W, 220V,and 100W, 220V are connected in series across 220V supply the ratio of current through them will be-

Ans. 1:2

Q. Two heaters, rated at 1000 W, 250 V each are connected in series across 220V supply. The ratio of current through them will be-

Ans. 250W

Q. Ratio of resistances of a 100W,220V lamp to that of a 100W, 110V lamp will be that the respective voltages-

Ans. 4

Q. Four 100W bulbs are connected in parallel across 200V supply line. If one bulb gets fused-

Ans. Rest of the three bulbs will light

Q. A 200W, 230V lamp is connected across 112V supply. The will draw power-

Ans. Slightly more than 50W

Q. If the voltage across the lamp drops by 1% the power drawn will be reduced by-

Ans. 2%

Q. A 200W, 100V lamp is to be operated on 250V supply. The additional resistance required to be connected in series will be-

Ans. 75 ohm

Q. 1 Kwh is equal to-

Ans. 860 Kcal

Q. A 100W watt light bulb burns on an average of 10 hours a day for one week. The weekly consumption of energy will be-

Ans. Pt/1000kwh

Q. An ideal voltage source should have-

Ans. Zero source resistance

Q. For a voltage source, terminal voltage-

Ans. Cannot exceed source emf

Q. Constant voltage source is-

Ans. Passive and bilateral

Q. An ideal current source has zero-

Ans. Internal conductance

Q. Which of the following statements is incorrect an active element?

Ans. Resistance

Q. The terminals across the source are……. If a current source is to be neglected-

Ans. Open-circuited

Q. An active element in a circuit is-

Ans. Current source

Q. A bilateral element-

Ans. Resistor, inductor

Q. The circuit having same properties in either direction is called-

Ans. Bilateral circuit

Q. The element which is not capable of delivering energy by its own is called?

Ans. Passive elements

Q. A network having one or more any energy source of emf is called-

Ans. Active network

Q. A circuit having neither any energy source nor emf source is called-

Ans. Passive circuit

Q. A passive network has-

Ans. Neither current source nor emf source

Q. For determining the polarity of the voltage drop across a resistor we do not require value of-

Ans. Resistor, current

Q. Kirchhoff’s lawn are valid for-

Ans. Both linear and non-linear circuits

Q. According to Kirchhoff’s voltage law the algebraic sum of all IR drops and emfs in any closed loop of a network is always-

Ans. Zero

Q. The algebraic sign of an IR drop primarily depends upon the-

Ans. Direction of flow of current

Q. Maxwell circulating current theorem-

Ans. Utilises Kirchhoff’s voltage law

Q. While Thevenizing a circuit between two terminals V_TH is equal to-

Ans. Open-circuit terminal voltage

Q. Thevenin’s theorem Z is determined by-

Ans. Open circuiting all independent voltage source and short circuiting all independence current source

Q. Theorems applicable for both linear and non-linear circuit is-

Ans. Norton’s

Q. While determining R_TH in Thevenin’s and Norton’s equivalent are mode dead-

Ans. Only voltage source

Q. According to fuse law the current carrying capacity varies as-

Ans. (diameter)^1.5

Q. The rating of fuse wire is always expressed in-

Ans. Ampere-volts

Q. The insulation on a current carrying conductor is provided to prevent-

Ans. Current leakage, Shock

Q. The thickness of insulation provided on the conductor depends upon-

Ans. Current rating

Q. When a heater is connected to the power supply the heater coil will glow but the supply wiring does not glow. This is because-

Ans. Internal wiring is of superior material

Q. Lamps in street lighting are all connected in-

Ans. Parallel

Q. Energy meter for connection has,

Ans. 6 terminals

Q. Electric battery is a device that-

Ans. Generates emf by chemical action

Q. EMF of a zinc-carbon cell is about-

Ans. 1.5V

Q. The depolarize in a carbon zinc cell-

Ans. Converts the hydrogen produced into water

Q. Capacity of a dry cell is-

Ans. More when it supplies current intermittently

Q. Cell commonly used as standard cell is-

Ans. Mercury cadmium cell

Rate of Chemical Reaction & Chemical Equilibrium in Hindi

Q. Internal resistance of primary cell varies-

Ans. Inversely with the surface area of electrodes

Q. The internal voltage drop of a voltage source-

Ans. Depends upon internal resistance of the source

Q. A voltage source of emf E volts and internal resistance r ohms will supply, on short circuit a current of-

Ans. E/r amperes

Q. Cells are connected in series in order to increases the-

Ans. Terminal voltage

Q. When two batteries of unequal voltage are connected in parallel the emf of the combination will be equal to the-

Ans. Emf of the large battery

Q. When two cells are connected in parallel it should be ensured that they have-

Ans. Equal emfs

Q. Cells are connected in parallel in order to increases the-

Ans. Current capacity

Q. For a group of cells when internal resistance of the group is equal to external load resistance the group will deliver maximum-

Ans. Current

Q. Electric supply for electro-deposition should ha-

Ans. Dc voltage

Q. In a lead acid battery the level of the electrolyte should be-

Ans. Above the level of plants

Q. In a lead acid battery the energy is stored in the from of-

Ans. Chemical energy

Q. The lead acid batteries-

Ans. It does not deliver current on putting its components together until it is supplied electrical energy from an external source

Q. During discharging of lead-acid cells, the terminal voltage decreases with the decreases in-

Ans. Discharge rate

Q. In a battery ,cover is placed over the elements and sealed at the top of the battery container to –

Ans. Exclude dirt and foreign matter from the electrolyte

Q. Petroleum jelly is applied to the terminal of the lead acid battery in order to prevent-

Ans. Corrosion

Q. For keeping the lead acid battery terminal free from corrosion it is advisable to-

Ans. Apply petroleum jelly

Q. In a lead acid battery, separators are provided to-

Ans. Avoid internal short-circuits

Q. In a lead acid battery, fillers are provided to-

Ans. Facilitate flow of gasses

Q. Tests performed for ascertaining whether the battery plants are defective or not is-

Ans. Cadmium test

Q. In lead acid batteries, sedimentation occurs due to-

Ans. Over-charging at high rate

Q. In a lead battery, excessive formation of lead sulfate occurs due to-

Ans. Idleness of battery for a long time

Q. Condition of a fully charged lead acid battery cannot be ascertained by-

Ans. Color of the electrolyte

Q. Emf of a land acid battery-

Ans. Increases with the increases in specific gravity of the electrolyte

Q. If the specific gravity of the electrolyte in a lead acid cell increases beyond 1.23 there will be-

Ans. Increases in internal resistance

Q. Capacity of a lead acid battery does not depend upon-

Ans. Charge rate.