Find the resistance (in mega Ω) of a wire of length 10 m, cross sectional area 1 cm2 and made of a material of resistivity 100 Ωm.

Find the resistance (in mega Ω) of a wire of length 20m, cross sectional area 1 cm2 and made of a material of resistivity 200 Ωm.

A

40

B

4000

C

80

D

2000

Two wires have the same material and have the same volume. However wire 1 had cross sectional area A and wire 2 has cross sectional area 3A. If the length of wire 1 increases by ∆x on applying force F, how much force is needed to stretch wire 2 by the same amount?

A

F

B

4F

C

6F

D

9F

Find the resistance (in mega O) of a wire of length 10 m, cross sectional area 1 cm² and made of a material of resistivity 100 Ohm.

A

1000

B

20

C

500

D

10

Find the resistance (in mega ohm) of a wire of length 8 m, cross sectional area 2 sq.cm and made of a material of resistivity 120 ohm m.

A

1920

B

4.8

C

2.4

D

960

Find the resistance (in mega) of a wire of length 20m, cross sectional area 1 cm² and made of a material of resistivity 200m.

A

40

B

4000

C

80

D

2000

A telephone switchboard 100 pair cable can be made up with either enameled wire or tinned wire. There will be 400 soldered connections. The cost of soldering a connection on the enameled wire will be P 1.65 on the tinned wire, it will be P 1.15. A 100- pair cable made up with enameled wire cost P 0.55 per linear foot and those made up of tinned wire cost P 0.75 per linear foot. Determine the length of cable run in feet so that the cost of each installation would be the same.

A

1,000 feet

B

1,040 feet

C

1,100 feet

D

1,120 feet

Two monochromatic waves having frequencies $$\omega $$ and $$\omega + \Delta \omega \left( {\Delta \omega \ll \omega } \right)$$ and corresponding wavelengths $$\lambda $$ and $$\lambda - \Delta \lambda \left( {\Delta \lambda \ll \lambda } \right)$$ of same polarization, travelling along X-axis are superimposed on each other. The phase velocity and group velocity of the resultant wave are respectively given by

A

$$\frac{{\omega \lambda }}{{2\pi }},\,\frac{{\Delta \omega {\lambda ^2}}}{{2\pi \Delta \lambda }}$$

B

$$\omega \lambda ,\,\frac{{\Delta \omega {\lambda ^2}}}{{\Delta \lambda }}$$

C

$$\frac{{\omega \Delta \lambda }}{{2\pi }},\,\frac{{\Delta \omega \Delta \lambda }}{{2\pi }}$$

D

$$\omega \Delta \lambda ,\,\omega \Delta \lambda $$

In the gate area for non-pressurized casting gating ratio a:b:c? (gating ratio = a: b: c where, a = cross-sectional area of sprue, b: cross-sectional area of runner, c = total cross-sectional area of ingates).

A

1:2:2

B

2:2:1

C

1:4:4

D

1:4:2

A wire having an area of cross section = 10sqm and another wire having an area of cross section= 15sqm, have the same length and are made up of the same material. Which wire has more resistance?

A

Both have equal resistance

B

The 10sqm wire has higher resistance

C

The 15sqm wire has higher resistance

D

The value of resistance cannot be determined from the given data

Two copper conductors have equal length. The cross-sectional area of one conductor is four times that of the other. If the conductor having smaller cross-sectional area has a resistance of 40 ohms the resistance of other conductor will be

A

160 ohms

B

80 ohms

C

20 ohms

D

10 ohms

Find the resistance (in mega Ω) of a wire of length 10 m, cross sectional area 1 cm2 and made of a material of resistivity 100 Ωm.

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