If the angle of wrap on smaller pulley of diameter 250 mm is 1200 and diameter of larger pulley is twice the diameter of smaller pulley, then the centre distance between the pulleys for an open belt drive is

The layout of a shaft supported on bearings at A & B is shown. Power is supplied by means of a vertical belt on pulley B which is then transmitted to pulley C carrying a horizontal belt. The angle of wrap is 180’ and coefficient of friction is 0.3. Maximum permissible tension in the rope is 3kN. The radius of pulley at B & C is 300mm and 150mm. Calculate the tension in the rope of pulley C.

A

6778.3N and 7765.3N

B

5948.15N and 2288.75N

C

5468.4N ad 8678.3N

D

None of the listed

The layout of a shaft supported on bearings at A & B is shown. Power is supplied by means of a vertical belt on pulley B which is then transmitted to pulley C carrying a horizontal belt. The angle of wrap is 180’ and coefficient of friction is 0.3. Maximum permissible tension in the rope is 3kN. The radius of pulley at B & C is 300mm and 150mm. If allowable shear stress in the shaft is 70N/mm² and torsional and bending moments are M=1185000N-mm and m=330000N-mm, find the diameter of the shaft.

A

36.8mm

B

39.7mm

C

44.7mm

D

40.3mm

The layout of a shaft supported on bearings at A & B is shown. Power is supplied by means of a vertical belt on pulley B which is then transmitted to pulley C carrying a horizontal belt. The angle of wrap is 180’ and coefficient of friction is 0.3. Maximum permissible tension in the rope is 3kN. The radius of pulley at B & C is 300mm and 150mm. If bending moment on point B in horizontal plate is M and in vertical plane is m, then the net bending moment at point B is?

A

M

B

m

C

M+m

D

√M²+m²

The layout of a shaft supported on bearings at A & B is shown. Power is supplied by means of a vertical belt on pulley B which is then transmitted to pulley C carrying a horizontal belt. The angle of wrap is 180’ and coefficient of friction is 0.3. Maximum permissible tension in the rope is 3kN. The radius of pulley at B & C is 300mm and 150mm. Calculate the torque supplied to the shaft.

A

453.5N-m

B

549.3N-m

C

657.3N-m

D

None of the listed

In a flat belt drive, if the slip between the driver and belt is 1%, between the belt and follower is 3% and driver and follower pulley diameters are equal, then velocity ratio of the drive will be

A

0.96

B

0.97

C

0.98

D

0.99

Two pulleys are connected by a belt. The sum of the diameter of two pulleys is 90 cm and while the one makes 50 rpm, the other makes 20 revolutions. What will be the diameter of the pulleys?

A

19.7cm, 70.3 cm

B

23.4 cm, 68.7 cm

C

25.7 cm, 64.3 cm

D

21.1 cm,63.2 cm

Two pulleys are connected by a belt. The sum of the diameters of the pulleys is 92.6 cm and while one makes 50 rev/min the other make 200 rev/min. What will be the diameter of the pulleys?

A

18.53 cm, 74.07 cm

B

19.65 cm, 64.89 cm

C

20.01 cm, 78.09 cm

D

17.69 cm, 69.90 cm

The ratio of belt tensions $$\frac{{{{\text{p}}_1}}}{{{{\text{p}}_2}}}$$ considering centrifugal force in flat belt is given by where,
m = mass of belt per meter (kg/m)
v = belt velocity (m/s)
f = coefficient of friction
$$\alpha $$ = angle of wrap (radians)

A

$$\frac{{{{\text{p}}_1} - {\text{m}}{{\text{v}}^2}}}{{{{\text{p}}_2} - {\text{m}}{{\text{v}}^2}}} = {{\text{e}}^{{\text{f}}\alpha }}$$

B

$$\frac{{{{\text{p}}_1}}}{{{{\text{p}}_2}}} = {{\text{e}}^{{\text{f}}\alpha }}$$

C

$$\frac{{{{\text{p}}_1}}}{{{{\text{p}}_2}}} = {{\text{e}}^{ - {\text{f}}\alpha }}$$

D

$$\frac{{{{\text{p}}_1} - {\text{m}}{{\text{v}}^2}}}{{{{\text{p}}_2} - {\text{m}}{{\text{v}}^2}}} = {{\text{e}}^{ - {\text{f}}\alpha }}$$

Two pulleys of diameters d1 and d2 and at distance x apart are connected by means of an open belt drive. The length of the belt is

A

π /2 (d1 + d2) 2x + (d1 + d2)2/4x

B

π /2 (d1 – d2) 2x + (d1 – d2)2/4x

C

π /2 (d1 + d2) 2x + (d1 – d2)2/4x

D

π /2 (d1 – d2) 2x + (d1 + d2)2/4x

Two pulleys of radii r₁ and r₂ and at distance x apart are connected by means of an open belt drive. The length of the belt is

A

$$\pi \left( {{{\text{r}}_1} + {{\text{r}}_2}} \right) + \frac{{{{\left( {{{\text{r}}_1} + {{\text{r}}_2}} \right)}^2}}}{{\text{x}}} + 2{\text{x}}$$

B

$$\pi \left( {{{\text{r}}_1} + {{\text{r}}_2}} \right) + \frac{{{{\left( {{{\text{r}}_1} - {{\text{r}}_2}} \right)}^2}}}{{\text{x}}} + 2{\text{x}}$$

C

$$\pi \left( {{{\text{r}}_1} - {{\text{r}}_2}} \right) + \frac{{{{\left( {{{\text{r}}_1} - {{\text{r}}_2}} \right)}^2}}}{{\text{x}}} + 2{\text{x}}$$

D

$$\pi \left( {{{\text{r}}_1} - {{\text{r}}_2}} \right) + \frac{{{{\left( {{{\text{r}}_1} + {{\text{r}}_2}} \right)}^2}}}{{\text{x}}} + 2{\text{x}}$$