Jharkhand TGT (JSSC) Mock Test - 1 - Jharkhand (JSSC) PRT/TGT MCQ

It is given that, the coordinates on which the line joins are (1, 2, -3) and (-2, 3, 1)
Let the direction cosines be l, m, n
Let  be two point which joins the line.

Now, we know that,

Putting the values according to the question, in equation (1), we get,

Putting the values according to the question, in equation (2), we get,

Putting the values according to the question, in equation (3), we get,

The given equation is,

Integrating both side, we get,

We know that,

and

We also know that,

If then

Let

Equation of normal to plane and passing through (1, -2, 3)

Let,

∴ (x - 1) = 2r ⇒ x = 2r +1

And, y + 2 = 3r ⇒ y =3r - 2

Also, z - 3 = -r ⇒ z = -r + 3

i.e., (2r +1, 3r - 2, -r + 3)

Consider Q be the the image of given point

∴ Q = (2r +1, 3r - 2, -r + 3)

Let, R be the midpoint

∴ R =

⇒ R = (r + 1, - 2, + 3)

Since R lies on plane 2x + 3y – z = 7

2 (r + 1) + 3 ( - 2) - ( + 3) = 7

⇒ 2r + 2 + -6 + - 3 = 7

⇒ 4r + 4 + 9r -12 +r - 6 = 14

⇒ 14r - 14 = 14

⇒ r = 2

So, image Q = (2(2) + 1, 3(2) - 2, -2+3)

⇒ (5, 4, 1)

Given:

As we know,

Now,

By Pythagoras theorem,

The value of ,

The required value is .

Given are in .

So we can write

(i)

Given equation of straight line is (ii)

Comparing (i) and (ii)

So lies on the line.

Cut-off Region of a Junction Field Effect Transistor is also known as pinch off region.

Cut-off Region is also known as the pinch-off region where the gate voltage, VGS is enough to cause the JFET to act as an open circuit as the channel resistance is at maximum. The Pinch-Off value of the JFET refers to the voltage applied between Drain and Source (with the Gate voltage at zero volts) at which maximum current flows. Operating with the Drain/Source voltage below this value is classed is the "Ohmic Region" as the JFET will act rather like a resistor.

Sink is a heat reservoir at a lower temperature T₁ from which the engine rejects heat. The sink has an infinite thermal heat capacity. In the sink, any amount of heat can be added to it without changing the temperature.

The magnetic moment of a magnet is a quantity that determines the torque it will experience in an external magnetic field.

It is considered to be a vector having a magnitude and direction. The direction of the magnetic moment points from the South Pole to the North Pole of the magnet.

The magnetic field produced by the magnet is proportional to its magnetic moment.

In the first case, the ray of light is converging, when passing from lens , so it is a convex lens. In the second case, the ray of light is diverging, when getting reflected from the mirror , so it is a concave mirror.

The rate of heat transfer in a conducting rod will increase by decreasing the length of the rod

As the heat transfer rate is directly proportional to cross-sectional area and temperature difference of the rod. So by decreasing the area and temperature difference, the heat transfer rate will also decrease. So option (A) and (B) are wrong.

As the heat transfer rate is inversely proportional to length of the rod. By decreasing the length of the rod, the heat transfer rate will increase.

A transistor can be made to operate as a switch by operating it in saturation region and the cut-off region.

The transistor is a three-terminal device. If it were to be used as an amplifier or a switch, it is supposed to be a two-port device. For a two-port device, four terminals are required. One port is referred to as an input port where the signals are fed into the network and the other port is the output port, where the response of the network is available. When both the junctions are forward biased, the transistor is said to be in the saturation region. When both the junctions are reverse biased, the transistor is in cut off region.

If the circuit uses the Bipolar Transistor as a Switch, then the biasing of the transistor, either NPN or PNP is arranged to operate the transistor at both sides of the I-V characteristics curves. The areas of operation for a transistor switch are known as the Saturation Region and the Cut-off Region.

The Zener breakdown occurs in the junctions which are heavily doped and the avalanche breakdown occurs in the junctions, which are lightly doped.

The avalanche breakdown is a phenomenon in which there is an increase in the number of free electrons beyond the rated capacity of the diode; This results in the flow of heavy current through the diode in reverse biased condition. Avalanche breakdown occurs in lightly doped diode

Zener breakdown mainly occurs because of a high electric field; When the high electric field is applied across the PN junction diode, then the electrons start flowing across the PN-junction. Consequently, it develops little current in the reverse bias. The Zener breakdown occurs in heavily doped diodes.

As we know,

and

When the current is ,

....(1)

When the current is doubled,

.....(2)

By equation (1) and equation (2),

So, if the current in the wire is doubled then the heat produce will become four times.

A non-stick surface can reduce the ability of other materials to stick on it. These surfaces are coated with a synthetic polymer called teflon. Non-stick cookware and the flat end of an electric iron are coated with teflon.

A diagonal relationship is said to exist between certain pairs of diagonally adjacent elements in the second and third periods (first 20 elements) of the periodic table.

These pairs are (lithium (Li) and magnesium (Mg), beryllium (Be) and aluminium (Al), boron (B) and silicon (Si).

Magnesium and Lithium are almost the same sizes and electronegativity values are nearly the same.

Therefore, Magnesium and Lithiumthe showing similar properties to each other.

Sphalerite ore : ZnS

Calamine ore : ZnCO₃

Siderite ore : FeCO₃

Malachite ore : Cu(OH)₂.CuCO₃

It is possible to separate two sulphide ores by adjusting proportion of oil to water or by using' depressants'. In case of an ore containing ZnS and PbS, the depressant used is NaCN.

Nylon threads are strong, elastic and lightweight. A nylon rope is actually stronger than a steel wire. Hence, it is preferred for making parachutes. Harness straps, suspension lines, tents, sleeping bags, sails, rope, tennis strings, fishing poles and lines, etc. are also made from nylon fibers because of their strength.

When primary amine reacts with chloroform in ethanoic KOH, it follows carbylamine reaction and the product formed is an isocyanide. Isocyanide is also known as carbylamine. Isocyanide gives off a very offensive odor, so this reaction is also used as a test for primary amines.

In general from left to right in a period, ionistion enthalpy increases due to effective nuclear charge increases.

But due to extra stability of half filled and full filled electronic configuration, required ionisation enthalpy is more from neighbouring elements. i.e., first ionisation enthalpy order is:

Al < Mg < Si < S < P

Electronic configuration of Chromium (Cr).

Cr- 1s² 2s² 2p⁶3s²3p⁶4s¹3d⁵

Since propyne has a triple bond, therefore it has minimum bond length.

We know that

The redox half cell reactions are written below:

Only copper shows positive value for electrodepotential of of 3d-series elements. The rest of the metals are good oxidizing agents with

The Kjeldahl method is not applicable to compounds containing nitrogen in nitro and azo groups and nitrogen present in rings (e.g. pyridine, quinoline, isoquinoline) as nitrogen of these compounds does not convert to ammonium sulphate under the conditions of this method.